The problem with all of these decentralization-is-bad write-ups is that they miss the forest for the trees -- including the ones that point out that non-technical people can't run their own servers. If it's a fallacy to attempt to re-decentralize the Internet then we might as well just give up and stop using it then. Let's surrender absolutely everything we do on the Internet to these big companies. A technological democracy cannot exist without decentralization.
XMPP, Mastodon, etc. aside the Web became centralized largely because we who built for the Web let it happen. The Web used to be a lot more decentralized where we, the people who built stuff for the Web, wrote in our blogs and helped each other learn this thing we were at the same time developing standards for to improve. This all ended when almost all of us converged on Twitter.