I wrote a counter-point to this a while back: https://wedistribute.org/2024/05/forking-mastodon/

I’m not saying “don’t do it”, but realize that the amount of commitment required to make a hard fork even moderately successful is vast.

It’s telling that the biggest project in the space is barely able to pay more than a handful of people to work on it, and it still develops at a snail’s pace. Notably, those are the people who deeply understand the system and its internals. While it’s not impossible, you have to be realistic about how much further a group can get when they don’t have the insight or technical chops required to take development further.