Meta’s Twitter alternative promises that it will work with decentralized platforms, giving you greater control of your data. You can hold the company to that—if you don't sign up.
I this this requires some more subtlety: defederating from a corporate-controlled competitor can prevent Embrace/Extend/Extinguish.
Meanwhile, I think it would be perfectly sensible for businesses to create their own Fediverse instances on their own domain to control their social media presence, and avoid paying to be recognized as who you are. Communities on their instance could replace the once-ubiquitous forums.