Yes, but HTTP is not legacy. It powers nostr too. You have to remember DNS was a small tool, by Jon Postel that was hooked on to HTTP at the time because it was useful You can think of DNS assomething like HTTP-NIP-05. But it just grew and grew. And when things grow, centralization creeps in. If nostr made an alternative to DNS and it grew the same size (it wont) the same, if not worse, centralization would creep in. Nostr nor http are tied to DNS anyway. Nomen for example is an excellent solution there. NIP-05 is pretty secure, and provides rich profiles on the web.
Discussion
HTTPS is great. Unfortunately most think you need to be blessed by a browser root program and CA to use it. Part of that capture has been mitigated by Let’s Encrypt (thank god) and there are other schemes like DANE (domain authentication of named entities) where you can self-generate and self-register your own cert using DNSSEC. But the browser vendors/CAs have little interest in implementing because that cuts them out of the authority loop.
It’s not so much centralization I am worried about; it’s more about authority-creep that leads to centralization.