SimplestBitcoinBook on Nostr: I hear that, but how would they prove they are legit with their npub? Like what would ...

I hear that, but how would they prove they are legit with their npub? Like what would I ask them to do to prove themselves?
Feel like I’m missing something here but no idea what it is 😅

Sachin (npub1xnc…3qnl) suggested trusting the one with most follows by people I trust, which could work but could also be misleading since I don’t know if they were misled.