It seems contradictory to say that Tilt is an abstraction over kubernetes and say that won't work at scale, but then volunteer ops to be a layer of abstraction over kubernetes as a solution.
FWIW, Skaffold.dev is similar to Tilt, and has been working out great. "skaffold dev" on the cli or the corresponding button in the users IDE starts up a local kube cluster (minikube), the dev code in a container, any other configured containers, optionally opening a port to attach a debugger, and watches the code for changes and restarts the container with the dev code when there's changes. Developers aren't beholder to the capacity of whoever's on call on the ops team to manage the containers they need to be productive. The details of pods and CRDs and helm and ArgoCD and kubectl are abstracted away for them. They just run "skaffold dev" and edit code. Ops gets to run "skaffold render" to build and tag images, and generate the corresponding kubernetes manifest.
Ops is not a layer of abstraction over Kubernetes no more then Dev is layer of abstraction over Python. We both have different responsibilities and thinking that Ops is just missing one more library is why it goes so wrong.
Kubernetes is massive beast and I get it. It feels extremely overcomplicated for "Please for the love of all that holy, just run this container." However, trying to abstract away such complexity is like trying to use Golang with some Python to Golang cross compiler. It works until it you need some feature and then oh god, all hell breaks loose.
I have not played with scaffold either but I will say. scaffold render should not be Ops job, I find it goes best when Devs present artifact they believe is ready for production and I can slot into the system. Otherwise, the friction between Devs handing Ops what they think is possibly buildable artifact quickly becomes untenable.
FWIW, Skaffold.dev is similar to Tilt, and has been working out great. "skaffold dev" on the cli or the corresponding button in the users IDE starts up a local kube cluster (minikube), the dev code in a container, any other configured containers, optionally opening a port to attach a debugger, and watches the code for changes and restarts the container with the dev code when there's changes. Developers aren't beholder to the capacity of whoever's on call on the ops team to manage the containers they need to be productive. The details of pods and CRDs and helm and ArgoCD and kubectl are abstracted away for them. They just run "skaffold dev" and edit code. Ops gets to run "skaffold render" to build and tag images, and generate the corresponding kubernetes manifest.