A big difference between Marvel/DC and MHA is the fact in MHA most are born with powers, with it being an explicit 80% of the population while in Marvel/DC people with powers are still the minority and unlike in MHA they aren't always born with their abilities, you got people like Batman or Iron Man who use tech, people like Spider-Man or Flash who got their powers through accidents and even comparing to the X-Men the X-Gene is unpredictable it could lie dormant for 50 years before activating while in MHA it could be determined during childhood whether or not you're born with a quirk.