I'm not saying I totally agree with the original comment there, just confirming that they meant it.
If you own your clients, sometimes you can say "it's on you to retry" (deadlines and retries are effectively mandatory, and often automatic, at Google). Having user facing services hand out bad addresses / endpoints would be really bad.
However, even for things like databases, you really want to know who the leader / primary is (and it's not really okay to get a stale answer).
So I dunno, some things are just fine with it, and some aren't. It's better if it just works :). Besides, if the data isn't changing, the write rate isn't high!
The thing is service discovery is _always_ inconsistent. By the time you get your set of endpoints from your discovery, it can be out of date by the time you open your socket. Certainly for something like databases you need followers or standby leaders to reject writes from clients - service discovery can’t 100% save you here.