When labbing and testing, what are your go-to services you setup as part of your mock network (e.g. SSH, FTP, HTTP, iperf, ?)

When setting up a test lab/homelab for networking what are you go to end host services you setup to test connectivity too to make the network feel more than solely a "network protocol" configuration lab?

Currently my lab does not have any type of services, it's all just mocking up with loopbacks or routed interfaces. Does anybody go further with things like Clusters, ESXi hosts or anything that would be deemed "exotic" for Network Engineers or is it enough what I have listed in the title of the post?

From the Network Engineer perspective is it good to dabble in a little bit more of the server side to understand the network from the "user side" as opposed to purely the network side? I find a lot of people in my team are really weak on ESXi and other "user applications" as they're mostly network heads and have no interest in what's attached.