It's a clean UX for receiving, for sure.

But what if the payment fails after you hit the tip button? What if you navigate away from the page before I can tell you it failed? What if the receiving user's node is offline?

There's also the issue of spending limits. If you connect SN to your node, you don't want SN to be able to spend all your money. AFAIK node permissions are not granular yet. We'd have to connect to an lnbits instance or something to get decent granularity.

Anyway, I don't expect you to have the answers. I only mean to demonstrate it's non-trivial to provide a good non-custodial UX for a product like SN.