Maybe a local proxy, deployed with the service, is a good answer to my objections, rather than having a centralised approach. This can help in polyglot environments, but remove any limitations a centralised solution would impose. Something like Istio would be an agent a service connects to locally, used for service discovery, complex routing or rate limiting. The configuration is service specific. Load balancing is done by "dumb" proxies, like in the old days.
Maybe you don't understand how Istio works. The Envoy proxy is locally deployed as a sidecar next to each process. The centralization is entirely for the control plane. The local proxy uses the centrally managed configuration for making local decisions about routing.
