That's not true. Mastodon replicates all your posts to a bunch of other servers you don't control by design, which makes them harder to erase.
It's no worse than normal internet publishing, but it doesn't magically solve the erasure question.
It's no worse than normal internet publishing, but it doesn't magically solve the erasure question.
Nostr fixes both of these. So whilst you're at the mercy of relays storing your data, you can at least be anonymous.