If Resident evil can get good performance despite its transition into a yearly release, largely based on being able to work on an existing engine (from RE2), then Pokemon has no excuses.
But eh, they didn't have an excuse for shitty gameplay, pacing, performance, stupid decisions, and a whole bunch of things either.
SwSH's engine has been out for years and the company is rolling in money.
Arceus had some QoL changes because it was not mainline (despite how many people argue it might be) so they have some flexibility.
This shit won't change unless they bleed money and with GO and merchandising? That's never going to happen.
The bar keeps getting lowered and they get away with it because every time they release a new title, they pour the money into marketing to cover up a mediocre game.
Rinse and repeat for every title, the reason they add new mechanics is NOT that they are experimenting but because they can market it as new functions and do an entire campaign allowing it to generate interest+money, no matter how shit it is. And they know it won't stay, they will remove it and make another mechanic (that is similar to others but tweak so people won't notice) and do the entire marketing cycle again.
For an AAA and a flagship/console seller equivalent, there really is no excuse for this to be this but the consumers allow it as long as it's cute and casual and as long as everything is shiny and nice so the company gets away with it every time.
What happened to BDSP was fucking illegal.
I work in Business and have some experience with Marketing, and I can say for certain that there is little to no soul given to the gameplay side of things but every action is entirely made based on monetary returns instead of what makes a game fun or respecting the og fans. The Pokemon mainline series and how the company has developed throughout the years is an insanely good case study to do and look at.