What you’re describing took place with on-prem iron as well - nothing cloud about it. At all.
Service discovery is in part DNS with low ttl, but there’s a part of it that ties in to configuration management, monitoring and observability as well.
If you “update dns” that means you’re doing a part of what consul does (only f ex nomad does it for you). Nothing magic, but you still “need it”.
Tags and metadata is a large part of it though, as well as configuring things automatically based on state of the SD and K/V.
In the end - whatever works, I guess.
