Answering your question, if I were Shueisha I would make it mandatory for official licensors to post at least 50 free episodes of the anime/100 from the manga on their platforms. If someone is, for whatever reason, interested in trying out One Piece, this old story that's 25+ years old, I say they should get a "free" sample. The kind of free sample they give you in Vegas, they give you free liquor so that you get drunk and lose all your money. You get 50 free anime episodes, you get hooked and then you pay a monthly Crunchyroll fee.
They are doing this in Japan right now with the manga, I think, and I hope it works. As for the anime, i think in Japan, at least, it's free to watch on Youtube.
Also, as others have pointed out, the live action can't do bad for the franchise. It's not like if the live action is bad any old readers/watchers will stop loving the franchise. But people that even like it a bit might get interested in consuming the story thru other mediums, and that's what hopefully happens, that the Live action brings new fans to the franchise, be it in USA or globally.
This was my answer for people in the US (And outside Japan). But what I have pondered was more like "What does ONE PIECE need to do to get more Japanese readers/viewers?" You might be thinking.. What? One Piece is already the best selling manga of all time. Yes, you are right, and yet there was this manga Kimetsu no Yaiba that, for whatever reason, broke all records ever.
Tbh I have always thought of One Piece as underperforming, even in Japan itself, where i know it is a massive phenomenon, but I always thought One Piece deserved even more sales. Think of it like this, Harry Potter, per book sold around 50 million copies, One Piece has sold around 5 million copies per book, that's what I am talking about. And now, more than ever, I believe One Piece deserves more sales (however ridiculous it might sound haha, I know it is the best selling manga of all time) and Kimetsu no Yaiba confirmed it for me, because if that manga gets those sales, the best story ever told should get even more… But I digress.
I asked this myself because with the current trend there is no denying that Kimetsu no Yaiba, for whatever reason, brought so many new readers of manga in Japan. Like KnY happened, then a year after there is this manga Jujutsu Kaisen that breaks records too (Not to the level of KnY but it did get to the same level of manga sales - and even surpassed- One Piece had at volume 16, 50million), also Tokyo Revengers has sold, just this year around 16 million copies and it will very likely at least sale 20million before Oricon year ends.
Keep in mind Naruto, at its peak, sold 6 million in a year, One Piece in most years sold around 10 million or so, and now the hot manga are breaking those records with ease. That's thanks to the Kimetsu wave and One Piece, while it's not necessary, should try to get some of those fans.
One Piece as a property has old fans, which is not bad, but if it just panders to their established audience, it will lose the part of the pie of the new audience.
Recently it was announced on twitter that something would be announced along with episode 1,000 of the anime, in all likeness it will be a movie announcement but I'd hope for a remake. But I have had this idea in my mind which I think would be perfect for One Piece and would solve the majority of issues new people as long as old times fans have with the series.
Btw, just throwing this, One Piece has become more popular on the US and worldwide just not on the same level or quickness as other series like Chainsawman and My Hero Academia and even Junji Ito works in the US. Last year manga exploded in popularity to levels never seen in the USA and other parts of the world. One Piece has been being reviewed now by book readers (not manga readers) and I feel like it could explode in popularity soon (I am eagerly awaiting this month's top 20 NPD BookScan Top 20 Adult Graphic Novels, last month was a surprise because HXH #1 and Naruto #1 got a spot on the list, I think the One piece 3-in-1 #1 have a decent chance of maybe getting a spot).
Ehem.. Anyway, this was my idea of what would make One Piece more popular, not only in the USA, but worldwide. The idea would be to make a modern remake of One Piece with better pacing. DUH! Easier said than done, right?
Well, let me tell you HOW it could happen and make financial sense for Toei and all involved parties while solving the anime's main issues which are its number of episodes, its "bad" art and its pacing (which admitedly it is horrible in the anime after episode 400ish).
The idea would be that Toei either started a seasonal One Piece remake that they could call whatever… One Piece: Romance Dawn or something like that.
OR that they remade the series while still animating the Wano storyline.
(btw the remake would be with current Wano's art style or something like the drama's animation art style, something more modern looking than Oda's original style)
I think the safer approach would be the 2nd one. And it would also solve the anime's horrible pacing. The way to do it, I think, could be something like this:
They remake an old saga, East Blue for example with 39 episodes, then continue adapting the manga's current material for 26 episodes (and good pacing) then they remake Laboon to Chopper's story in 2 seasons (26 episodes) continue with the manga's current material adaptation for other 26 episodes, then they do Alabasta's remake for 26 episode and so on.
If you counted right the this hypotetical remake would be at episode 91 while covering material that the previous anime was covering until episode 130.
Oda said last year that the manga is about 5 years from ending, and while I don't think that's the case anymore due to the COVID breaks, and stuff, I do think we should expect One Piece to end in 5 or so years from now (So around 2026-2027, I'd say 2027, as it would be the manga's 30th anniversary), but anyway I am talking about this to see how much time is left for the anime to conclude.
If the manga finishes on 2027, then the anime would end around 2028-2029.
With that in mind, and assuming Toei remade at least 26 episodes per year, starting this year (I truly hope that's the annoucement they will make one episode 1,000) by 2029 we would have 8 seasons of 26 episodes, that would be 208 episodes. Those episodes, if adapted with good pacing, or even "a bit rushed" pacing (like current remakes usually do, just look at Shaman King's remake or even TOEI's own Dai no Daiboken remake which covers around 3.5 chapters per episode.
208 (Episodes) x 3 (Chapters per episode) = 624 manga chapters covered, while One Piece's pre-time skip content goes all the way to chapter 597, so that's almost 27 extra chapters. So there's some room for TOEI to go slower when needed.
One Piece is a very wordy manga, but I think covering around 3 chapter per episode, especially for the fights while being slower in flashbacks and the more dramatic parts would be optimal. Still, 208 episodes could very well be enough to cover the pre-time skip portion of the manga and leave some room to be slower on the dramatic parts.
TOEI certainly has the resources to do this. If a series like Saint Seiya Omega existed for a whole 97 episodes, there is no way something like a One Piece remake is not feasible commercially. Think of all the new fans it could bring, all those figurines of old characters, the 100+ volumes, etc
They should do this in order to pander to a demography of people that have never seen/read One Piece, I know that One Piece doesn't need this but, in my opinion they are losing 20+ years of fans (plus 2 million people that, stopped buying the volumes over the years) that they could capture with a remake. (And that's only in Japan, think of all the people that would watch the remade episodes worldwide, they would know of course that the series is super long, but it would be easier to digest if a remake is made.)
Heck, worse case scenario TOEI can just try this idea for a 39 episodes remake of East blue and see how sales (Both inside and outside of Japan) go.That would also give them some room to adapt manga content because right now thanks to all of Oda's (well deserved) breaks, the manga and anime are very close.