If you are using a hosting provider, you are by definition not "self hosting", since you are in fact, not hosting (unless you happen to own the hosting provider company).

I actually self-host tools, and that involves having (in my case) a couple of rackmount servers in my spare bathroom, and an rPi5 with a 4x m.2 hat on my desk. Hell, even just running stuff on your own desktop/laptop is self-hosting.

But PaaS and SaaS are just as not-self-hosted as IaaS is. It's literally cloud hosting.