I just wrote something extremely similar, but it's only internal right now.

I personally find that the service mesh value-prop is hard to justify for a serverless stack (mostly Cloud Run, but AWS Lambda too probably), and in situations where your services are mostly all in the same language and you can bake the features into libraries that are much easier to import.

Observability is a great example of this. In serverless-land, you're already getting the standard HTTP metrics (ex request count, response codes, latency, etc), tracing, and standard HTTP request logging "for free."