It works at
Disneyland because the number of fast pass rides is lower and the clientele are mostly locals. There aren’t a ton of people jumping in to the parks first thing in the morning to grab fast passes. Even with that, I’ve run in to problems multiple times where it’s difficult to get fast passes for the popular rides because someone else grabs the time I’m going for on one of the popular attractions
Disney World has a mostly non-local clientele. More people going to Disney World would buy maxpass which would overwhelm the system. Unless you rope dropped a park, it would be nearly impossible to grab the top tier rides. Disney IT is already shaky and I don’t think they’d be up for this task. It would end up like ROTR boarding groups but it would happen at every park every day. It sounds like a nightmare to me.