Part of what happens in these arguments time and time again is that nobody is defining what the upper level of these mythic martials can do. We get vague allusions to characters with different abilities, but no real limits.
* On the lower end, you have Hawkeye. Peak human athlete, expert marksman, Avenger. But nearly all his abilities are within human bounds. The 5e martials I feel capture that level well.
* Then you have Captain America. Super soldier via serum. Above human peak, but not overly so. He's stronger, faster, more durable, and has enhanced senses. Still, he's not breaking the laws of physics with his abilities, but he bends them ever so slightly.
* At the high end, you have Superman. Alien powered by the sun. Impossibly strong. Resistant to most normal weapons. X-ray vision, hearing across the world. Flight. Super speed. Frost breath, heat vision. Cunning intellect. So far above mortals he can be likened to a God.
Clearly, there are other layers in between, this is not an all the nothing, but it kinda defines the low, middle, and high.
Where do we put the epic fighter? For some, Hawkeye is the limit. Others it's Cap. Still more want something closer to Superman. You can't build a class that appeases Hawkeye people if they are getting Superman, and vice versa. So when someone says "I don't want Superman, I want Captain America" and people respond with "Why do you want fighters to not even be Hawkeye?" communication breaks down.
Honestly, until someone takes the time to concretely lay down WHAT the limits are and what that epic fighter is doing, this argument is pointless.
