>>57176629The point being made is that between mortal freaks of nature and other Legendaries and Mythicals, there may well be five Pokemon better than any Mew at any single task meaning any measures of power aren't going to go excellently, but by being a meaningful contender in ALL OF THEM the lack of any "truly" standout benchmarks is severely underselling.
It's an angle that doesn't get much credit, having neither novel esoteric absurdities nor spectacular extremes of force, but makes for a complete fucking mess to deal with if applied at any serious depth. As you yourself note, this has never been done on-screen because they go at things by little more than whims.