The argument seems to be that if your attacker is stupid enough to only change your NS records and doesn't know about DS records, then DNSSEC will provide some protection.
It is not clear with ICANN mentions this, because somebody hacking your registry account (or somebody hacking your registry or the registrar) are attacks DNSSEC cannot protect against.
Re:ICANN urges adopting DNSSEC now
by quicksilver03 on Saturday April 20, 2019 @01:44PM
(#19707800)
A threat model where the attacker is assumed to be stupid is a very weak threat model. Better to assume that the attacker is at least as knowledgeable as you are.
Isn't that a bald-faced lie? The attacks in question are "someone stole my credentials and told my DNS provider to change the records to point elsewhere", as I understand them. DNSSEC merely protects against DNS spoofing on the internet backbone (not everywhere, because you're not supposed to turn out in when querying your ISP's DNS server, so the last mile isn't protected).