There is a Monero Nostr client but its adoption seems to be limited, I’m not as apposed to other coins in the end it’s a user choice, but to say Monero has bigger adoption might be a stretch. Cashu is not Bitcoin in the sense that it doesn’t have the same custodial properties but its still sharing the same unit of account. So no, your statement needs work 😄 just see Cashu as layer 2.5 it extends lightning into a space where it can function slightly programmable on Bitcoin standard but you do sacrifice custody of it ( side note 99% of lightning address on Nostr are custodial wallet providers )