I really hope not, because the recent retal builds I have seen posted have several impossible green items.
And I am sure that 90% of the player base do not even care about rankings anyway. 90% of the player base does not even play ultimate at all.
ARPGs have this tradition that in order to push the hardest content, you need to be somewhat of a nerd and spend time theorycrafting, testing stuff, farming etc. That is what I think is the most fun part about ARPGs - that I can really get into the details of the game and progress.
If you “just wanna have fun” you can play the other difficulties or just be content with SR 50 or something. If there was no challenging end-game and theory crafting etc, I would not play Grim Dawn.
But I have “beaten ultimate” numerous times, with SSF characters. Not super hard, and there are plenty of beginner build guides you can study and also build journals one can use as inspiration. Such things narrows things down for lesser ambitious players, they do not need to reinvent the wheel but have something to fall back on. What I am trying to say, you do not need to have fully geared chars to beat ultimate, you need some carefully chosen core items, cover resistances etc and just play well.