You mean like DNSSEC DANE?
The blast radius of that is every subdomain of whoever got compromised. Having only ICANN being capable of breaking the entire internet is a world of difference from what we have today, and may be the best we can do... and we should be using that, but it's not perfect either.
It's not ICANN in that system, it's the TLD operators, and the problem with that is that for many TLDs and all the most important ones, you'd be adopting a system where your keys are directly managed by institutions we already know to have misissued. The most important TLDs are state-controlled, which is why you saw DOJ notices on piracy sites rather than NXDOMAINs.