If you are under the impression that the martial classes are the most powerful in 5e, the only thing I have to say is that you need to learn to cast spells and you probably need to learn to evaluate classes on what they're capable of doing besides just damage per round (DPR).
DPR is actually a very limited metric and usually isn't good at measuring anything but how martial classes compare to one another. An alternate way of measuring class effectiveness could be "actions denied" or "action economy manipulation". This would be a lot more time consuming and require a lot more specifics about a given situation, so it isn't hard to see why people usually aren't doing that. So let's take a hypothetical example.
F***** amen to that. Plus all theorycrafters forget about movement, cover, conditions that can imposed on both sides, etc...
Edit: My hot take is that mobility is only as good as the features it can be used to support.
Is however the worst metric for martials by far since it's actually the weakest class of all game, once you go into proper evaluation and not only "raw damage against 10 AC target practice" like most people do.
Fighters are a pretty solid choice for DPR, if that is all you're looking for. Greatsword Fighter is barely behind Blastlock Baseline even when not using resources or feats (2d6 + modifiers vs 1d10 + 1d6 + modifiers) and Action Surge is a powerful burst ability. Add on something like Battlemaster and you'll have a pretty solid DPR character.
So I picked Fighter vs a Wizard having to stand soo as sort of a best case scenario in a comparison between DPR and casting in the martial class' favor.
I do understand however why you'd pick it for your reasoning, since it has basically nothing else than "hit and get hit". ^^
Overall, I simply don't understand though why so many people try to pit martials and casters against each other when all are so complementary.
Yes and no? The major problem with martials vs casters isn't so much the Wizard v Fighter in an actual party, but Fighter v Ranger / Paladin. Or Fighter v Fighter/Caster multiclass. Etc.
My experiences as a DM, occasional tabletop player, and in both Solasta and BG3 is that both Paladins and Rangers (even single class, non-Gloom Stalker ones) get all the dpr they need at most actual lvls of play (1-12, rarely higher) while also getting access to the spellcasting feature.
Casters only party has a high chance to be wiped before even getting to 5th level because low hit dice, overly reliance on spells for self-preservation instead of offense and laughably low mundane damage (capped as "simple weapon attack" up to 11th level except for Booming Blade and Agonizing Blast). Martials here act as protectors and give proper baseline for damage.
I think you're underselling how resilient casters are relative to martials, even if we ignore how easy it is to get access to armored casting etc. Given the expected dmg numbers, martials typically can't survive more than 1 additional attack compared to a caster. Having 1 regular attack also makes them almost on par with martials as weapon users until lvl 5, which is... problematic.
Martials only party has a high chance of steamrolling most fights until level 6-7 then get hit by a brick wall first time they face largely overnumbering group, smart enemies using bait or kiting tactics, or enemy magic.
They also have a hard time standing out prior to lvl 5 unless they pick up the Spellcasting feature, like Eldritch Knights, Arcane tricksters, Paladins and Rangers. Barbarians can succeed in very combat heavy campaigns, but will run out of steam faster than casters with only 2-3 uses of Rage.
Casters here act as threat mitigators by controlling vision, movement or ability to act.
At higher level, casters can be one-shot by many dangerous creatures unless they happen to have the right defensive feature ready and good Constitution, while (many but not all) martials will be useless against high speed / invisible / resistant / high AC creatures.
Really, I don't see how people fail to see the bright complementary of all classes between one anothers...
Parties are definitely better when you have complimantary characters. It's just a bit unfortunate that martials with spellcasting compliment casters better than martials without spellcasting.