That's a whole separate issue. Firstly, I don't know that I agree that "not doing supernatural stuff" is actually that important, particularly in light of how magic items have historically been used to fill the gap, just not in a particularly player agency forward way.You underestimate the appeal of "Badass Normal" characters. They're prodigious in fantasy fiction (consider Conan the Barbarian, John Carter of Mars, or Beren son of Barahir) and often quite beloved both classically and currently (consider Sokka from AtLA, or Batman, particularly DCAU Batman.)
There are absolutely folks who love D&D that would feel explicitly excluded if you told them, "No one is allowed to be Badass Normal in this game."
Even if it is though, then you're going to have to disappoint those people by the time allowing rewriting of the rules of reality several times a day is on the table, so supporting them has a lot more to do with expanding play options and offering alternative scaling/campaign off ramps before high levels kick in. It's design malpractice to print a class that can't compete.