@hekathegreat
Yes UT is a "full" GNU/Linux on the OS part, but a secure mobile oriented one, so you can't install snap ou deb packages in its default state.
On android phones, it runs on some android parts, most of them are vendor drivers, and it needs to use vendor Linux custom kernel to make phone work properly, but nothing from what you do on UT is shared with google (unless you want to, i.e. by using a google account) or any other entity.
Default installed apps have nothing to do with google, contact, messaging, phoning apps, and all the others are from ubports and opensourced and of course ubports doesn't collect your personnal data.
On openstore (wich only require account if you want to review apps) it's the same, only specific apps that has to do with google or youtube account can share some data with google.
Apps on UT are strictly confined, except core apps and some other, reviewed by ubports team.
Search "halium" and HAL (hardware abstraction layer) to better understand how UT works on android native phones.