I think that's a fair point -- you're making a tradeoff. And the best part is that you don't need to choose one or the other.

In my case, I find that I prefer having higher fidelity and simpler service code by using Tilt to avoid mocks. It's also nice for frontend development because, using a Kubernetes ingress, you can avoid the need for things like frontend proxies, CORS and other development-only setup.