A natural network effect will pull in users in a network. Watering down our decentralized network with Metas network will make all of Fediverses advantages indistinguishable from the users perspective. Decentralization is not something you experience as a user anyway so there will be no obvious reason for someone coming from threads to switch over to the Fediverese. The other way round is more likely. Meta has insane design and market power to push out better Apps, faster CDNs and marketing to give users a better "Fediverse".