DNS-over-HTTPS doesn’t make as much sense to me as DNS-over-TLS. They are effectively the same thing, but HTTPS has the added overhead of the HTTP headers per request. If you look at the currently in progress RFC, https://tools.ietf.org/html/draft-ietf-doh-dns-over-https-04 , this is quite literally the only difference. The DNS request is encoded as a standard serialized DNS packet. The article mentions QUIC as being…
One of the use cases for DNS-over-HTTPS given in the draft was to allow web applications access to DNS directly via existing browser APIs.
It's not worth the complexity of multiple protocols that do the same thing. And it's not worth making the base system insanely complicated so that the magic 4 letters 'http' can show up.
TLS? Yeah, since the simpler secure DNSes failed, we might as well use that. But let's try to keep http complexity contained.