The whole argument hinges on falsehoods. They argue that participation is optional in the current web ecosystem and that's just simply not true, not only for the web as a whole, but individual fiefdoms too.
Try getting a job without LinkedIn. Try buying a phone that doesn't run android or iOS. Try selling an app without sharecropping an app store. Try running a browser that's not based on chrome or Firefox.
And there's others with slightly more choice, but not a lot, email, social media, link aggregation, music platforms. All with just a small few main choices.
And the other argument is that feudalism stiffled innovation with its rigid hierarchies, that that's exactly what we have today with a few platforms having all the network effect, and killing off innovation. Small Web is dead. Small forums are mostly gone. Used market place is hidden behind a Facebook login wall.
Technofeudalism is here, you have no choice.