DNS over HTTPS Explained
blog.apnic.net
blog.apnic.net
The HTTPS connection stays alive but idle for seconds, maybe minutes, and it always has the capabilities that DNS can only get by punting to TCP, which requires a round trip.
At the layer above the TLS connection can be brought back quickly from cached credentials using a PSK
And at the layer above that the TCP connection can do Fast Open so that there isn't a round-trip there either after the very first session.
The main drawback of DoH itself is it moves DNS to a session based service which causes increases in workload for DNS infrastructure but to be fair the article does mention that so I'm not sure "it doesn't discuss the problems with DoH" is totally fair.
https://wiki.archlinux.org/index.php/Dnscrypt-proxy#Local_DN...
I wonder how they're going to have to work with things like the Australian/NZ censorship which I believe is based on DNS?