Not really. Nostr, for example, allows you to sign your posts with a private key and publish them to any server (relay). There are lots of protocols like that.
There's a guy called "silverpill" who is working on adding that to the fediverse.
nostr:npub1pqp7xnrmdxn6vzqspdmnuy8s5pag66uhmxhzljjh29t0gm4yuxrq0ce753 nostr:npub16fsxfvylsvlmv9fz3k7rga3wxl50plm8q708wgkwdr555lczlc5qu7xw8z nostr:npub1y6dsk2qtn8j8ynd02uv2dj8yztzey6wvgu48pdrjkxk0phkfr09q4a9hq8 nostr:npub192klhzk86sav5mgkfmveyjq50ygqfqnfvq0lvr2yv0zdtvatlhxskg43u7 I mean I COULD log off of fedi sure, but my friends are there
It's either someone else's instance or my own