It doesn't even have to be some microservices monster, just trying to bin-pack a bunch of different services, even monoliths, onto a fleet of servers.
If I did it how the usual "k8s is only for FAANG scale" people tell me to do, I'd go bankrupt ;)
Granted, we use Nomad, not k8s, but we definitely need a scheduler and definitely are not reaching Google-scale.