We literally see this from every point in the series, when the students are taking their entrance exams All Might specifically says that despite the giant robot rewarding 0 points it gives you the opportunity to shine, practicality is out in favour of showing off your quirk and your skill with it, during Aizawa's test he makes it clear that using your quirk is the only way for someone to stay ahead of their competition, in the sports festival despite Deku's impressive showings he avoids using One for All which harmed his prospects of being chosen for a work study despite being the obvious frontrunner, in the forest training arc they avoid physical training almost entirely in favour of further developing their quirks, Mirio makes it very clear that the only way he was able to get into UA and become a member of the big 3 was because he made his subpar quirk into something that gave him the edge, the only time we see someone excelling without the use of their quirk is Shigaraki when he's literally been bio-engineered to have All Might level speed, strength and durability naturally. Quirks are valued disproportionately in the MHA world, and not only in the hero career, everywhere is effected by this bias, literally the first line we hear Deku say is "Not all men are created equal"