Why doesn't it matter? A VPS is still someone else's computer. They could be monitoring what you're doing on there because they run the hypervisor and they have physical access.
For me at least self-hosting is mostly about having control of a computer/server software wise, not physically. That is probably an important differentiator from homelabbing, which is more focused on controlling the hardware. You can combine the two, but for self-hosting you don't need to physically control the hardware.