What I’ve seen is that most vendor solutions aren’t flexible enough. Many firms have their own on-prem and data privacy restrictions that make hosting model training artifacts on a vendor’s servers impossible, and it’s way easier to sell building in house.
I’m very surprised you are hearing that nobody is using MLflow and Kubeflow (though Kubeflow has a lot of genuine usability and bug problems). I am hearing the exact opposite. Everybody, from tiny 5 person startups to giant ecommerce firms is just spinning up simple stuff for model tracking, mostly around MLflow.