but your ISP will still be able to see all your connections even if you don't use its DNS servers unless you use a VPN... this just spreads the information to a third party.
Downvote me all you want, but domain names are still being sent to the ISP unencrypted, as of TLS 1.3... so it doesn't matter who processes your DNS queries, your ISP still knows everything about which sites you are accessing... but anyways, bare IP addresses still reveal a lot (metadata)
wrt esni the anonymity pool is definitely the set of content that can share the same address pool. In a world with lots of CDNS (and several multi-CDN switching services) this covers a huge amount of content - but I agree - not everything.
If you think about the best/worst case scenario, would you be happy if one CDN would deliver everything? I think that we would be in a worst situation... ideally, I think that everyone would have their own servers and that your ISP would not even be able to see which IP addresses you are talking too (completely decentralized)