Obviously you need to enable local verification for DNSSEC to do anything in the first place, otherwise the DNS server can just lie about the DNSSEC status. If someone is manually configuring a DoH resolver, they probably have a toggle to do DNSSEC validation nearby.

DNSSEC doesn't prevent censorship, but it does make tampering obvious. Moving the point of trust from my ISP to Cloudflare doesn't solve any problems, Cloudflare still has to comply with national law. DoH is what you use to bypass censorship; DNSSEC is what you use to trust these random DNS servers you find on lists on Github somewhere.

A bit over half the websites I visit use signed zones. All banking and government websites I interact with use it. Foreign websites (especially American ones) don't, but because of the ongoing geopolitical bullshit, American websites are tough to trust even when nobody is meddling with my connection, so I'm not losing much there. That's n=1 and Americans will definitely not benefit because of poor adoption, but that only proves how much different kinds of "normal internet user" there are.