The big thing that articles like this miss completely is that we are no longer in the brief HTTP/1.0 era (1996) where every request is a new TCP connection (and therefore possibly a new DNS query).

In the HTTP/1.1 (1997) or HTTP/2 era, the TCP connection is made once and then stays open (Connection: Keep-Alive) for multiple requests. This greatly reduces the number of DNS lookups per HTTP request.

If the web server is configured for a sufficiently long Keep-Alive idle period, then this period is far more relevant than a short DNS TTL.

If the server dies or disconnects in the middle of a Keep-Alive, the client/browser will open a new connection, and at this point, a short DNS TTL can make sense.

(I have not investigated how this works with QUIC HTTP/3 over UDP: how often does the client/browser do a DNS lookup? But my suspicion is that it also does a DNS query only on the initial connection and then sends UDP packets to the same resolved IP address for the life of that connection, and so it behaves exactly like the TCP Keep-Alive case.)