You already rely on your ISP for IP transit anyway… so no issue there. Hardware and SSL termination/app layer is where it matters
Discussion
100%
Even just data residency and path. I would not want customer data or sensitive business data to be stored on cloud servers whenever possible.
That's exactly how I see it! However I'm thinking about setting up some edge caching for content, such as if I decide to start hosting media or assets for customers. That would take a lot of load of my uplink, and cut back latency and allow for some better locality.
It depends on your use case. Self hosting *everything* and by that I mean literally everything is a bad idea and a waste of time.