something that i think gets often overlooked when talking about how mastodon sucks is that the software itself is awful. people talk a lot about instance drama and shitty admins etc and that stuff is real but really, the software is just bad. it's a resource hog, it has a lot of missing or broken features, the source is unnecessarily complicated (because rails), etc. everyone hates the dude who maintains it, too, because he has made it so hard to contribute to the project that everyone who used to be an active contributor has fucked off rather than deal with his bullshit. in other words, it's exactly like every other open source project.
theoretically the benefit of the activitypub protocol is that one could write alternative software to interface with mastodon instances, and people have done this, but they all also suck. there's pleroma, which is fine software but many instances defederate all pleroma instances on sight because of a perception that only nazis and pedophiles use pleroma. there's misskey, which again is decent software but the main contributors are all japanese, which isn't a problem inherently obviously but the language barrier has led to some significant miscommunications. i've spoken to several people under the impression that misskey was abandoned despite the fact that no such abandonment had ever happened.
(not to mention the fact that the existence and possible superiority of alternative options makes the narrative around pitching activitypub to people substantially more complicated)
something i came to realize while working on the open source streaming platform that i made with my friends is that federation is just... not very useful. there's a lot of theoretical benefits, but the truth is... the internet is already decentralized! if cohost goes down in flames i can always move somewhere else. i don't need any kind of special protocol layer on top of the web in order to do that. there are a lot of mastodonites who i've seen concerned about what happens if "proprietary" social networks like cohost make bad choices that drive people away, or run out of money, etc, and the truth is that mastodon/activitypub... doesn't solve those issues. as long as you always have multiple ways of reaching your friends, your audience, etc, there's really... nothing to be afraid of.
i think the future has room for things like cohost, that are designed to be big tents that draw in a diverse crowd of people to meet each other and interact (which is what twitter has been, and still sort of is, at least for now), and for niche forums with a small group of weirdos, and for tiny group chats with a dozen or fewer people posting about their lives, organizing hangouts, sharing stuff they like.
a lot of people who are drawn to mastodon/activitypub are drawn to the idea of having a permanent solution to talking to your audience online. they want to build something that can last forever, that will survive any contingency, that will ensure all our relationships and our data are preserved into eternity. the truth however, is that's impossible. there's nothing bad about the cycle of impermanence. places get built, people show up and hang out and then they go away. i'm on cohost knowing full well it will someday die. one day the web itself will die.
