While I like the idea of using blockchain-determined name ownership; there's a few problems. First, you have the problems that you get just because of how blockchains work[0]. But moreso there are specific chicken-and-egg problems with migrating away from standard DNS:
- Because DNS is well-established and everyone uses it, most websites want to be registered in DNS, and blockchain names provide little to no value to them.
- Because blockchain names see little usage, most ISPs see no need to resolve them in addition to or overlapping standard DNS names.
For a blockchain name system to actually succeed, you need buy-in from large network operators. Most network operators, for better or for worse, have just decided to trust ICANN and ICANN alone. At the very least, you would need IANA and ICANN to agree to set certain TLDs aside for competing naming systems so that network operators could be confident that resolving them wouldn't cause security problems.
[0] specifically the whole 'immutability' and 'no central authority' thing legalizes certain kinds of theft