we could - there's just the question of how to avoid fake data if anyone can post payment metadata to a public API endpoint
with the rss::payment spec the url to fetch the metadata originates in the payment comment - so there is a direct tie to the actual payment and since apps host the full metadata on a url their reputation is at stake if they fake data
I am open to exploring solutions to this where apps don't have to host the payment urls - and promise I won't mention nostr 😅