I’m sure there are more but here’s a few off the top of my head:

• The ability to defederate from any instance that tries. truthsocial.com and gab.com are based on Mastodon, and they’re cut off from the Fediverse because they’re “downhill” to put it lightly. If the instance you’re on starts acting funky you can just pack up and leave. If Facebook starts asking for your driver’s license where are you going to go? There is no other Facebook, and your friends wouldn’t be there if there was.

• The ability/culture for users to donate to their instance admins. Your instance admin should transparently list all their costs and donations, so everyone is aware how much is needed to cover infrastructure. Not counting volunteer hours, it’s very cheap to run these servers as long as the average person kicks in a buck every so often. The amount an average person needs to donate is probably like 5-10 cents a month, which can easily be covered by generous patrons. I personally donate about $10/month to my instance, which is way overkill and probably covers a significant chunk of their operating expenses (not that they need my money, I’m sure).

• No inherent need for people to use the software. No one is making money from higher site activity time, there’s no need to have black box algorithms that try to keep you engaged by promoting ragebait etc

• Decentralized nature makes it impossible to “buy it out”. Technically a company could probably coerce an existing Fedi server to sell so they can start causing chaos, but they can’t just drop $44 billion and nonconsensually steal the website from every user. Spread out among the servers and protections will only grow stronger.