DNSSEC and DoH DNS over HTTPS serve completely different purposes. There isn't a choice to be made between them. DNSSEC sole purpose is to validate the integrity of DNS records. DoH DNS over HTTPS protects DNS requests and responses in flight but does nothing to validate that the DNS record returned was actually created by the domain owner.

The author of the article states they don't care about tracking of requests by their ISP, so they don't bother to implement in flight protection of DNS.