Email definitely counts as a decentralized protocol. Sure, in practice, it's fairly centralized. Most people use Gmail. But you don't have to. That's the key.

Email definitely counts as a decentralized protocol. Sure, in practice, it's fairly centralized. Most people use Gmail. But you don't have to. That's the key. If for some reason you don't want to use Google's platform, you're 100% free of creating your own mail server. The crazy thing is that it will probably work out just fine. The mail client/server model is really popular. You can go ahead and DIY your email and use all the popular clients without issue (maybe except Gmail? idk). And sure, if you somehow become famous in a way Google doesn't like, they can effectively cut you off from lots of other people by not federating with your email server. In practice, though, this is probably pretty uncommon.