How important is it for networks to provide DNS servers? Couldn't a device usually get away with just using 2606:4700:4700::1111 or 2001:4860:4860::8888 all the time with SLAAC? Also, what about RDNSS?
So, I was less aware of RDNSS. That makes one of my complaints moot.
DNS is critical. I'm not talking about registering an endpoint into a local DNS server (mydesktop.local), I'm talking about the endpoint knowing who to ask about google.com.
I know DNS itself is critical. I'm asking whether network-provided DNS is critical, or if using well-known DNS servers like Google's or Cloudflare's would be good enough on most networks.
Do those return the correct CDN servers matching your geographical location and/or ISP?
I didn't try Google or Cloudflare specifically, but I did experimentally used some other DNS provider for a while, until I eventually ran into the problem that by doing so I got the "wrong" set of servers for anything hosted on Akamai, where the route between my ISP and those specific Akamai servers was grossly overloaded in the evenings.
Switching back to my ISP's DNS meant getting a more suitable set of Akamai servers and reasonable download speeds again.