A martial guy should be able to do that with mooks, sure. With equal-CR martial combatants, 50/50 -- he dies or they do. And you can hit that benchmark with a reasonable PB. But that's not all he should be able to do, so that he pretty much has to sit out any encounters that don't involve a mundane opponent walking up to him and offering to trade blows Queensberry-style.
So I still don't understand enough of what you mean by "competent" to tell if I even disagree with you or not.
Because if by "competent" you mean the benchmarks above, and by "reasonable" you mean the 25 PB you were saying earlier was "barely enough" to make a "competent" martial, then in my experience a well built martial can hit around those kind of thresholds with way less than 25 PB.
Conversely, if all you're saying is just "the martial-caster disparity is a thing that exists", then... sure, whatever. If someone with decent system mastery builds a caster designed to overshadow the martials, then yeah, the caster will probably be able to do it. I agree that's a legit issue that can be talked about. (Though preferably not in this thread, since it's not terribly on-topic.)
So if by "competent" you mean "can contribute effectively--without relying on help from party members--in a situation designed to push a well-optimized non-support full-caster to their uttermost limits, along all axes" then I could understand that. No serious disagreement.
But for me, if you can take a class/PB combination into a module and have it contribute meaningfully to a majority of the encounters therein, it meets the base standard of being at least what I would consider "competent".
And I have absolutely seen martials do that on less than 25 PB, so I don't see how it's necessary to being "competent" in that sense.