It's true that the concept of "cities" (or even just "gatherings of people") predates the Internet by thousands of years, and that cities themselves haven't adapted much to the Internet and what it enables in the 40ish years it's been around. This project was inspiring because it embraced what's possible in a new way and enabled many new possibilities that wouldn't otherwise be possible in the typical piecemeal upgrades a city typically sees over time (especially in terms of construction guidelines and sustainability). People hated on Sidewalk Labs since its very inception, but I guess they bit off too much area and got shut down by the locals (and, I guess, covid-19 made a handy exit strategy).
Hopefully the next EPCOT equivalent will either be a new city that attracts the kind of people who would want to live there, or at least find a city that would be happy to host their "experiments".
FWIW I previously worked at a "smart cities" company that I won't besmirch, but I will say I would rather see a more well-known (and IMO trustworthy) company that has more experience managing and securing data at scale than them. In experimental projects like these, it just takes one "city's data leaks" headline and the whole market chills.