Folks moving to Mastodon are swapping a service run by a capricious egomaniac for one where the admin of your home instance controls everything about your account. And you probably don't know what your server admin is like when you sign up. Is this really much better?

How is that different from email? I don't want to defend Mastodon too much here, it's still early days and a lot I don't know about it, but to me it seems there's a very strong parallel between both.

With email you can register a domain name, point it at an email provider of your choice, and thus decouple your email address from the provider you’re using. With Mastodon, if you want to control your own username you’d have to run your own instance, which is much more work.

Or are there Mastodon servers that allow you to bring your own domain name? Moreover, Mastodon admins seem to take a more active role in moderation (email provides filter spam and perhaps check for illegal content, but not much beyond), making the instance choice more important

you can build your own: @simonw has some info on that somewhere

I'm paying a company to run an instance for me I 💯 agree Mastodon would be better if you could bring your own domain without running your own instance. I don't think that's technically infeasible but it looks like no-one has built a Mastodon server with virtual host support yet