nohokum
Having been around the network for a few years now, and having talked up Urbit to countless people of countless different professions, political beliefs, ages, etc, I can confidently say: This isn't true.
It's just that a specific sort of Hacker News/Reddit gets agitated and makes a lot of noise on this subject whenever Urbit gets brought up.
Normal people who just want their digital lives improved aren't interested in these cringe 2010s-era blogosphere political beefs.
On Urbit you have ~65,000 potential star sponsors and can switch at any time. (Worth noting: after a year and a half on the network, I have not heard of anyone being refused service by any star.)
That's a clear difference from today's internet, where effectively all discourse gets siphoned off, by a series of vicious megacorporation incentives -- the need to lock you in, the need to serve you up manipulative advertising -- onto the servers of one of four FAANG companies. (I think we can safely remove the N at this point, but then the acronym ends up looking rather seemly.)