This is just my personal opinion:
In the anime, it was only mentioned for Kurogiri that it is rare for someone to have warping abilities.
Besides that, I believe one of the reason that people with unusual ability, such as Eraserhead, are not able to easily bubble to the top is because in order to use their quirks, they have to pay relatively higher cost (regardless the nature of the cost) than others, like Eraser head have
eye issues, which is now affecting his daily life
and also for Shinso, he
cannot activate his quirk by himself, and at least as of now, he cannot use his quirk freely as he please due to the stress it places on himself
Furthermore, since we know these are unusual quirks, it wouldn't be a surprise if people gang up on them to bring them down, just like
How the league of villians took down Eraserhead, though there were obviously handicaps that caused him to lose, but the fact remains is that, under certain conditions, he will lose
However, in All Might's case, people have tried to bring him down since forever. A good example is once again, the
league of villians. IMO, the only reason why he lost is because of his injuries from All For One. If it wasn't, he would definitely beat them - Which implies directly that he is just that overwhelming in terms of "Close range physical attack"
Therefore, they don't become top heroes, though they are definitely way above average.
The strength that Midoriya exerted even while wearing the support equipment broke, as it cannot withstand the pressure. Which means, at least as far as the science advancement in the show is concern, gadgets still cannot fully overtake physical quirks. However, this is obviously far-stretched, since One For All is literally the strongest quirk. However, in the general case. True, gadgets can easy supplement their physical abilities, but they would have to wield it to use it, and I'm sure it'd be much easier to break their gadgets. (IMO)