I'd love to know more about what you're thinking here.
I don't think we're replacing #Webfinger. I think we're trying to follow through on #WhatCorySaid at #FediForum (https://www.youtube.com/watch?v=7_Gs1t0qe78)
...which is basically: Let regular people take their account to a new server any time they want, without relying on awful XML/CSV import/export jobs. This would go a long way to solving Fediverse UX issues and preventing enshitification.
Is there more that I've missed?