The same counter argument applies here as to the corresponding football one (there are no great teams out there in competition with Dublin). If you take Cuala out of last years competition, and it becomes between the likes of Na Piarsaigh / Ballyea / Portumna / Thomas’s etc. and someone wins the final by a point, then these supposed lesser teams become great teams. But if you put a club like Cuala in there who beat them all easily, it just makes Cuala all the better - not any of the other teams more mediocre.
Likewise in the football, a team that wins a lot and sometimes easily, is better then a team generally that loses out every second year to a competitive team. I heard Vincent Hogan on the radio recently saying the same thing, that Dublin can’t be judged with the best because they don’t have a team chasing them as hard as Dublin v Kerry in the 70s or Cork v Meath later on etc. Apart from being disrespectful to Mayo, it is just flawed logic. Say for example, Kerry improved by another 5 points a game in the 70s, so beat Dublin every time and beat them easily - would that make Kerry a lesser team because they had poor competition. So by getting better, they actually get worse!