Future World wasn't as outdated as some think
It was very outdated. In both presentation and in specific content.. its themes or stories were not tho.
Just look back at the preshow video from USO for T2, BTTF, etc since you like Uni. Look at how poorly those 90s videos aged in presentation, style, graphics, sound, etc. The first gen EPCOT attractions suffered the same, and were almost 10 years older. Everything from hair styles, dress, video quality, etc. The 90s purple reboot aged just as fast. The 80s and the next 25 years were insane in how quickly things progressed and changed. The existing attractions could have been revamped and kept current with production quality, styles, trends, current thinking.. but they weren't and instead people wanted new attractions for their reinvestment (TT, JIYI, MS, etc) and not just a refresher. Communicore was its own trainwreck of lack of repeat value and aging.
Just look at UOE today.. with its horrible out of date Ellen and Bill Nye references. That choice of contemporaries in the attraction really hindered it as well in it's refresh. Look at how much T2 showed its age before they redid the preshow.
By the 90s EPCOT already felt stiff. It was only the addition of new attractions that kept it some what charged. It NEEDED refreshing.. badly. Sadly the one that probably needed it the least.. Imagination.. was the one butchered almost the worst
WoM was a sleeper - don't let people try to convince you otherwise. It's cool in Disney terms because of the general scale of the attraction and number of AA scenes.. but it wasn't a WoW ride. UoE had far more impressive effects, presentation, etc.. but was a bit dry for some. SSE and Horizons were the real winners in striking the balance of cool, scale, and optimism. Imagination was just pure Disney.. Land presented neat ideas and Seas was impressive as an aquarium for its time.