So I had only one step to do. Install Nvidia drivers. Used autoinstall. And surprise, surprise it broke something. Multitouch gestures stopped working. Spend multiple hours to realize it. Another drivers didn't help.
Anyway for me the general question was. How do I revert apt get commands? It seems kind of difficult. I could purge all nvidia stuff or whatever. BUT is there maybe some general solution? That is the reason I'm always afraid of apt upgrade. It may break something and I have no idea how to restore. But maybe it's just a newbie question. Is it?
Reverting an apt install is just apt uninstall packagename. Or maybe it’s remove-typing this from the hospital bed so I don’t remember for sure (going home later today though, doing well!)
I hate to recommend this, but if I were in your shoes, I’d just install another distro or OS in place of what you have just to PROVE whether it’s the hardware itself that’s broken, or if it’s only a software issue. If the hardware really is busted, reinstall the factory os-probably windows-then see if you can get it repaired or replaced via warranty. Just put it back into windows world so they don’t use that as an excuse to weasel out of honoring their warranty.
If Ubuntu works like Fedora in this regard, it probably switched from Wayland to Xorg when you installed the proprietary Nvidia driver. The Wayland session supports touchpad gestures natively, but the Xorg one doesn't. You can install something like libinput-gestures[1] to replicate the functionality, with the caveat that the gestures won't be triggered until you lift your fingers off the touchpad. (On Wayland the interface reacts to the gestures as you swipe.)
Ubuntu switching 'silently' to Xorg is actually working as intended because Nvidia's support for Wayland was somewhat experimental until very recently. It's getting better though, and it's now officially supported on Fedora 35.