@King:
It's a bit difficult to compare Izuku with Hatsume or Tony, considering they have access to all sorts of parts that the average teen wouldn't have. Even Hatsume is probably leeching off either U.A. or Power Loader in order to get materials for inventions. And Tony is a billionaire who probably considers any technology that's not science fiction level scrap.
Izuku's struggle is valid because he didn't really have anyone to help him out. Even Stain and Aizawa were hero students at one point, so their abilities could've been taught by someone else. Otherwise, you'd need time to become a veritable fighter like Knuckleduster.
I am not talking about Deku as we know him. I am talking about an alternate hypothetical story where Deku could be smart enough to make his own tech like Spider-Man. And the story would come up with whatever reasons it wants to justify that. It has been done in plenty of stories before, it can be done now (now being at the start of the series, not literally now it is too late unless that role gets handed to a new character lol). It all depends entirely on what Horikoshi wants to write because writing sci-fi means you get to bend a fictional world's scientific limits however you want no matter how surreal.
Here's an example: Deku's dad works at a junkyard or toy assembly line. Deku somehow gets access to junk or toy parts. This version of Deku is smart enough to make them into gadgets and armor. He barely passes the U.A. entrance exam using solely these tools or even improvising new items in the exam battlefield. Because he is just that smart and determined, no matter how ridiculous that is. Then gets accepted and gains access to U.A.'s resources as he tries to catch up with all of the supers as a Rock Lee/Tony Stark fusion.
Boom, there's your alternate reality Batman Deku series. When you start a series, you get to establish whatever rules or logic you want. Like superpowers or Devil Fruits or Chakra or spellbooks. The quality afterwards depends on how consistent and interesting that foundation is developed.
And I am not saying Deku should be super agile like Stain and Aizawa before high school without a teacher. Only that if he wants to believe he can be a hero, he should do some exercise since the world knows that Pro-Heroes and villains can train to become super agile and technical martial artists.
If the Hero Course knows that they can train people to be like Aizawa, Stain, Toga, etc… Then why is that not a thing? Why don't they have a program like that for kids with no Quirks or Quirks that suck? You can't tell me having mind control or Quirk erasure powers somehow makes you and only you perfectly fit for freaking mummy kung fu. Or that they can't have a program where they give those same kids support items as a main crutch since the more heroes the better.
@Jabberwok:
What if you're looking at this wrong? Maybe Deku is barely hanging onto his dream at the start of the series, with pretty much everyone in his life having endlessly beat his ambition down. Maybe Deku specifically doesn't expect to get into UA, and his application there is kind of his last long-shot attempt before giving up. It's pretty clear he's increasingly depressed and borderline suicidal right before he meets All Might. Initially, Deku's whole ambition is based on idealism and idol worship, which unsurprisingly didn't provide enough motivation to stave off the endless discouragement he faced from even the people who cared about him.
It's an idea I'd love to see addressed more later in the series, maybe through Mirio: what stops people with bad quirks or no quirks at all from becoming heroes isn't the lack of physical ability but society telling them it's impossible. It makes a pretty good addendum to the opening statement "Not everyone is born equal."
See, that is pretty much what my interpretation of chapter one was. Until the series kept going and I noticed that heroes and villains can train to be ninjas and Deathstroke-lite assassins without physical-amplification powers. Then it just makes Deku never working out and his plight with the people who criticized him look more… well, dumb. Because even if he is Quirkless and has no hope in himself, the public should at least know you can train to fight like a freaking ninja turtle in hero school/villain hardknocks even if you don't have superhuman physical stats. That is what is hurting my suspension of disbelief in hindsight. Why should I feel as sorry for Deku as the story wants me too if I reread and know that he can get bandage training like Shinso? And before you say how that is not part of the normal curriculum or whatever, then why isn't it? If your Mirio storyline idea can dig into that question with the Quirkless/bad Quirk discrimination, then that could retroactively fix all of this I guess.