I consider DNS one of the great success stories as far as internet protocols go. I remember (for a short time) updating host files and the emergence of DNS. DNS was created for a very different type of Internet then what we have today. It assumed a more “friendly” and cooperative Internet. Without amplified DDoS attacks, MITM attacks, and spoofing. Overall, DNS has survived pretty much in its original form with a couple of relatively small additions like EDNS 0 and DNSSEC (which nobody uses).