Just to clarify, I am not suggesting signing up on a random server with no track record. The server lists I linked to have very specific requirements to be listed (https://joinmastodon.org/covenant and https://fedi.garden/about-this-site/). Also, many of these servers have been going for years without problems. You can browse the servers on fedi.garden listed by year of foundation: https://fedi.garden/servers-sorted-by-founding-year/