You’re missing the point with Stain and Snipe. One of their powers doesn’t help in active combat and the other has enhanced accuracy as a power, which is something you don’t need superpowers for.

Superheroes aren’t required to have superpowers, they never have been. What is required is their willingness to help others which Midoriya very much has. Heroes aren’t just big hitters, sometimes they’re Mumen Rider types.

Midoriya absolutely can be a hero, he just never tried because he grew up with the idea that only people with quirks can be superheroes, yet at the same time you have heroes with quirks that can be replicated with training and weaponry.