Apps randomly turned on in “Apps using iCloud”?

I don’t and never intend to use iCloud. I have everything turned off in “Apps using iCloud”. But once in a while, I have to go to that to inspect, because sometimes a random app would be turned on.

(1) What does it mean to have an app turned on? I tried to log in to my iCloud account and could never figure out where those apps might be stored.

(2) Is there a way to turn it off completely? So I don’t have to always check like a hawk.

Note: version of this is also posted in iPhone@lemmy.ml, I have no idea how to crosspost on memmy. Sorry