There are many other problems with the concept, though of this one:

High-level blocks (domains, TLDs) can be bypassed using, say, dnsmasq, by providing specific pass-throughs.

As for sites that use widely-blocked services: the message is to feed back to them and tell them not to do that. The fact of countermeasures does not mean that there will be no collateral damage. In fact, that's kind of precisely the situation that got us into this mess in the first place: putatively legitimate advertising that isn't.

"Hey mum, blocking adverts is simple! All you need to do is install and configure dnsmasq, then configure some bypasses for sites that break!"

Yeah, sorry, no. As for reporting sites that break, that's a good thing to do in general, but not too good if you want to use the site now.

The "it's too complicated for the average user" is most of the "other reasons" I was referring to. Pi-Hole is far more streamlined (and largely reduces to "dnsmasq plus a lot of blocked domains").

My point was that if you're going the blockfile route, you can punch specific holes.