If a goalkeeper is at Dinamo Zagreb at 28, and the other is at United, I am sorry but I will think that there is a vast difference between them, and that is what the football world thinks too.
Do you know how ridiculous you sound when you post this? It is like saying that Anthony Elanga and Alejandro Garnacho are better than Cristiano Ronaldo, just because the former bunch plays for Manchester United, while CR7 plays for Al Nassr (let me know if you have the same opinion). Just because a particular player is not selected by ManU or RealM doesn't mean that they are bad. In club football, a lot of focus is on forwards. Usually the clubs don't spend a lot of money on goal-keepers. One exception is Manchester United, where David De Gea receives £19,500,000 per year.