When is a service mesh just too much for microservices?

Hey everyone, I'm starting a new microservices project and trying to pick the right infrastructure. I've looked at service meshes, things like Istio or Linkerd. They do give you a lot, like managing traffic, seeing what's happening, and security stuff. But I'm starting to wonder when they actually become more trouble than they're worth. If I only have a small number of services, maybe 5-10 to start, and they're pretty clear about what they do and don't talk in super complex ways, is a service mesh just extra work and complication? Or are there times, even with this small setup, when the good things about it still make the operational headache worthwhile?