It's childish contrarianism to want to outright reject Meta adopting activitypub.
There are plenty of reasons to be concerned about what this means and how to handle it but if you want this technology to matter in the slightest, it needs widespread adoption. Otherwise it's just a toy for the terminally online, technological masturbation, software solipsism.
Maybe you want the tech you use to be a toy forever, but I don't. I want these things to become standard, boring, in the background. You don't get there by rejecting every attempt at commercialization.