If your threat model involves spying on that level, sure, self-hosting at home is probably warranted. What I mean is that I'd rather have one powerful computer and the rest, laptop, phone, etc, use that resource instead of each device being an island. I don't want my files spread out over so many devices, I want access to everything from everything.

There is actually such a thing as encrypted computation, where the vm has no idea what it's executing. But it's slow as molasses.

Private if you trust the provider. Any system can be breached.