While I don't play anything outside of FFXIV, I've heard that FFXI used to have far more challenging content than anything FFXIV has ever brought to the table. Ultimate aside. Same for WoW, where they actually have in-game parsing add ons, if I'm not mistaken.
WoW and FF XI weren't the birth of MMORPGs. I'm talking about the old school: UO, EQ, AC, DAoC - Back when even voice chat was extremely uncommon (and was a game changer for raids) - The old school way was full of wonder and mystery.

You couldn't look up builds or optimized rotations. It was possible to run into a player who had figured such out, alone, on their own, and to only gape in awe at what they did which you might've never thought possible.

Where high end bosses, over years, might not be defeated because people couldn't figure out the mechanics. (There was one such in DAoC that was finally killed, one time, between all the servers, despite hundreds of attempts.)