I think the main innovation is actually climbing gyms and their popularity, and I'm surprised they weren't talked about in the article. For instance, Alex Honno

I think the main innovation is actually climbing gyms and their popularity, and I'm surprised they weren't talked about in the article. For instance, Alex Honnold replicated many of the difficult moves of Freerider in indoor gyms, which makes it logistically possible to train far more often and intensely. It also serves to further democratize the sport because you don't need the unlimited funds to travel to these spots in the middle of nowhere. The campus board was only invented in 1988 by Wolfgang Güllich while he was training for Action Directe. Now there's one hanging in every gym in the world. And I think Lynn Hill has said that one of the things that made her first free ascent of the Nose possible was new climbing gyms, that let her train more intensively than was possible before. So yeah, as the sport grows we also get more gyms, which further grows the pool of potential record breakers to those who can't travel as much.