I have considered something like that in the past. The problem is that you can't stop someone else from making a web frontend (with ads on it, of course) and now you're back to were you started.

Fairly straightforward to block such shenanigans.

I think Tor has done an amazing job at keeping those away who don't want to put effort into niche web-surfing, and those easily scared and/or duped into not discovering less-charted territories. Not to mention, it costs a LOT of money to mirror clearweb material on the deep web - and it's a grueling process. I wouldn't be surprised if the Internet was re-wilded in the context of Onion routing and Tor relays.