Exactly I think its a better approach than paid relays, not because paid relays are bad idea, they are good, but people need to pay and also have btc, ln, cashu, xmr or whatever you want to use. It's a lot less friction, as well as pow, and the user doesn't need a voucher to publish. Then this can be combined with a robust collection of policies for easy discard. I wish I had the time to build it. If you want we can keep in touch to brainstorm/develop
I'm starting to think about relay development a lot more. I'll definitely ping you if I start to really dig into writing my own relay. Writing a filter policy has been really interesting.
I was thinking to do a poc using khatru, nice framework to test and build