If the descentralization of social networks continue, we will have to prepare for the eventual rise of the instances wars, where people will start to fight about which instance is better and which one is weird to be in and so on, but that’s for the future of us all.
Mastodon is on a decline already. It is different than, say, Lemmy. Mastodon’s contents are produced mainly by mainstream content creators, and they do not migrate from Twitter its counterpart.