Minting ecash is an interactive process where someone needs to interact with the mint. In the case of a kind of "bridge" service, it could mint p2pk ecash for the receiving users (a bit in direction of npub.cash). You can avoid all that if the sender can talk to the mint directly.

 I think nostr:nprofile1qqstzfq9x083h745pwtmrhg7dlr8njel4ds0mzvj75u8hx0sg8tp0vcpzamhxue69uhhyetvv9ujumn0wd68ytnzv9hxgtc3vsuae did consider using ecash directly because its simplicity.