Most importantly you own your keys. You own your identity.
Imagine if you'd built a following on twitter with a particular ID and then someone (Elon) decided you shouldn't have it any more.
See: note1uqzm9whlcw0p5706v4z0eyeduvy2wllea6phrk0arsaz4gsc835sy6dznv
#NotYourKeysNotYourIdentity #nostr