I'd love to know more about BYOC. Does that apply to the raw data (e.g., the database lives inside the enterprise) or the entire application stack (e.g., the enterprise is effectively self-hosting the cloud).
It seems like you'd need the latter to truly be immune to cloud-vendor problems. [But I may not understand how it works.]
Here's how we do it for analytic systems: data and software. The software services are open source running on Kubernetes. If you don't like the vendor or the vendor goes away, the existing services keep running. You can also maintain them because the stack is open source.
This is different from what the local-first article is describing, which addresses data for individuals. That's a much harder problem to solve at scale.