p.s. Mastodon is part of the Fediverse, more info here:

➡️ https://fedi.tips/mastodon-and-the-fediverse-beginners-start-here/#whatismastodon

You can move your account and keep your followers & follows if a server is closing down:

➡️ https://fedi.tips/how-to-use-mastodon-and-the-fediverse-basic-tips/#WhatIfAServerClosesDown

For full independence, it is much cheaper and easier than you think to start your own server, more info here:

➡️ https://growyourown.services/grow-your-own-social-network/

The smallest Mastodon server starts from around $8 a month, and that includes the hosting company doing all the technical stuff for you.