Service meshes are hype. Maybe, not really, yet. They're still a lot of overhead (so many sidecars) but they do provide some valuable features. Wouldn't it be sad if every mesh implementation defined its own config, locking you in?
Service Mesh Interface or SMI is the proposed spec for standardizing access to service mesh features. Unfortunately, it is still very much alpha, and the spec is little more than the api CRD descriptions. The metrics API does seem the most fleshed out, but it does seem it will be a while fore it's fully ready.