You do realise that the argument that that site is presenting is false.

Firstly: "With TLS properly configured, DNSSEC adds nothing."

DNSSEC presents you with a valid, secure chain to know that the meta-data (encoded as TLSA) about the end-point you intend to communicate with is valid.

i.e. Grab the TLSA record for a hostname, validate the hostname (and TLSA record) via DNSSEC and then if the TLS certificate matches the details in the TLSA record you have confirmation that things are valid.

Secondly: "Securing DNS lookups isn’t a high-priority".

Then why there is a whole IETF WG dedicated to addressing it: https://datatracker.ietf.org/wg/dprive/about/

Thirdly: "The real threat to CAs is “the global adversary”

i.e. organisations like the NSA, GCHQ collating everything, everywhere.

Any reasonable person could spend an afternoon - not being paid - providing a counterpoint to each item raised. None of them are (currently) relevant and the only one that is/was is actually being address in the IETF working group linked above.