@BeAware I think a fundamental issue of Mastodon is that instance switching is so painful.
You can't migrate your posts & replies to them, so if you're someone who likes to build up a collection of posts and likes to see replies to those posts (for insights, useful links, etc) you are incentivised to stay. If you move, all of it is basically gone.
That's more of a protocol architecture limitation, I imagine.
I saw something about Firefish having a post importer, so I will check it out soon.