the key difference is delegation, if I sign a tx it cant be faked, if I say to binance to sign a tx in theory it could be the same unless at some point it is no more the same. Dns is delegation technology and a custodial solution designed when there where no alternatives. DHTs over relays signed by the party we want to communicate with (not the intermediary) need to replace dns, or at this point even twitter would be "good enough".