Nerds have been saying this about the HTTP-ization of protocols literally for decades, but HTTP's gradual assimilation of all other protocols has continued basically unimpeded.

Also: your primary objection to DoTLS is that networks block 53/tcp, and you say "same analysis applies to DNS over HTTP", except that, obviously, it does not: the whole reason DoH exists is to address that problem.

Finally, even though I believe over the long term that DoH will be successful and will eventually become the primary mechanism with which browsers look up hostnames, it doesn't have to be for DoH to solve, entirely, the real problems DNSSEC tried to solve.