That was always the problem.
D&D fans want to kill powerful demons devils fairies and undead who fly teleport and cast spell with the captain of the City Watch.
That's completely incorrect.
Unless the captain of the city watch is a character adventuring with a group in high tier levels. If a character can't deal with high challenge threats when they are at appropriate levels, then they aren't really at those levels. In old editions of the game, fighters were just worse than other characters at high levels without a ton of magic items. Starting with 3E we have expected some semblance of "balance" which to me means that those characters can participate at the same effectiveness at higher level play. 5E has infamously removed magic items from being a staple of the game, so a fighter can't really rely on them to be effective.
I answer this issue by saying that a high level martial character has supernatural powers because that's what they need to be a player in a high tier game, but that is not something that the designers and a majority of the players want to do.
There are answers to this: 4E answered it but people hated what they did to other characters. Pathfinder 2E does it, but the game is more complex than people like. 5E has done this to some extent by some of the subclasses and multiclassing, but the core fighter chassis doesn't address the issues that the fighter has with demons/devils/fairies and so on.
Without changes that the design team tells us aren't happening, a high level fighter can provide minimal support against high powered challenges where "hit it a lot of times" is not an effective solution.
As an aside, the Knights of Last Call did an excellent deep dive on the fighter in this
video. They eventually get into what PF2 does, but the first part of this video talks about the history of the fighter class from OE D&D on and discusses some of these issues. It's really good stuff if you weren't alive to experience this part of the game (and even if you were!)