Do you care? I tried mastodon long ago, was quickly disappointed in it, then disappointed in myself for getting my hopes up when the protocol itself didn't seem designed in good faith at all. Nostr, on the other hand, I kept coming back to until it stopped disappointing me, because some aspects of the design actually seem smart. The "bridges" show me posts I enjoy from Mastodon, but I don't think I necessarily trust the people making those posts if they're choosing mastodon over nostr. On the other hand, I don't really trust anyone without knowing Digit is safe.