The reason we didn't adopt Kubernetes Ingresses for Ambassador (https://getambassador.io https://getambassador.io) is more or less the same reason you cite in y

The reason we didn't adopt Kubernetes Ingresses for Ambassador (https://getambassador.io https://getambassador.io) is more or less the same reason you cite in your first bullet. The interface is too simple and while it may work for the simple case of configuring a reverse proxy it rapidly falls apart in the face of things like advanced API capabilities such as rate limiting, shadow traffic, canaries etc. It turns out these are things people really care about.