Found the two posts:
Discussion
Hello, I'm sorry if I made you uncomfortable. I have a question I want to ask you about Damus. What does my username appear as now? I can't see the username on some. My other question is that I see several people from one username. Is this normal?
Yep, anyone can have any username they want.
On Damus I see posts with @user, where does it go then when you click? Or ist that app specific?
Wouldn't it be better if everyone had a unique username like on Twitter?
That can only be achieved in a centralised service.
In nostr the keypair (public and private keys) is the only guaranteed unique identifier.
I'm still new here, but the mere existence of the concept "handle" feels kind of redundant. Seems like pubkey + display name would be enough.
I think it's fine for now, bit it'll become contentious when public figures join and they attract imitators. When that happens, integrations with other decentralised identity management systems (KILT protocol etc) will become more important, IMO.