You're close, but it's really when you have thousands of microservices using either shitty languages or shitty client RPC libraries where you can't easily perfo

You're close, but it's really when you have thousands of microservices using either shitty languages or shitty client RPC libraries where you can't easily perform client-side load balancing. There are plenty of languages and RPC frameworks where you can solve this without resorting to a service mesh. Practically, and to your point, service meshes solve an organizational problem, not a technical one.