Mastodon is a lot harder to enshittify being as it's decentralised and uses an open protocol.
If it looks like an instance has gone down the path of corporate enshittification, other instances will stop federating with it.
The software itself could be a target, but it's open-source. Even the original instance created by the software creators (mastodon.social), turns to the dark side, someone will inevitably fork the last open-source version of the software and other instances will then update from the most popular fork.
As long as the underlying protocol remains the same, it doesn't really matter what happens.
Heck, kbin is totally different software but uses the same protocol to federate with the various Lemmys, other kbins, and, yes, Mastodon instances too.
Consider what happened a number of times with Reddit where various groups left and used the last open-source version of the software to set up their own Reddit clones. It wasn't particularly successful for them, but one or two of them are still out there.
If there had been a large number of them all sharing content and posts like Mastodon etc., maybe they would have been more popular. (For better or worse).