I don't really see how this scales, on a global basis.
Sure, one or two of us running our own resolvers isn't going to hurt, but an extra hundred million or so resolvers would hurt -> at best just causes all the servers targeted by the resolver to add more layers of caching
Replying again as I did some research. It turns out there aren't actually only 13 root name servers, there are almost 2000. Also, the vast majority of queries to the root servers are from badly configured systems that aren't caching results properly or aren't even receiving the results. So running your own caching resolver, assuming it's working correctly, would contribute to the small drop in the ocean that is legitimate usage of the root servers. Presumably the same applies to the next levels up too.
It's a good point, I never really thought about it. In my case I'm reluctant to use my ISP servers because my country tries to practise censorship via DNS, but I also didn't really feel like using something like Google. I will do some research and experimentation with upstream caches like Quad-9 and Cloudflare to see what it's like.
Sure, one or two of us running our own resolvers isn't going to hurt, but an extra hundred million or so resolvers would hurt -> at best just causes all the servers targeted by the resolver to add more layers of caching