I have a brand new Lenovo Legion 5 with AMD Ryzen, Nvidia 1660Ti. This is definitely not a new hardware nor it has some strange spec. Standard, rather low end stuff for about $1000.
I've just installed Ubuntu 21.04 (the newest non LTS version) on it. LTS version cannot be used as touchpad will not work, as newer kernel is needed.
I decided to burn ISO on DVD and run installation from USB external drive. Installation started to work, but the drive was working like crazy, after 15 minutes of continuous squeaking I've stopped install and read the Internet. It turned out that installer is doing some "checks" and they take such long time that there is some timeout and it install is started again and again (obviously no clear information about what happened, only some cryptic warning info).
Lesson learned: it is virtually impossible to install Ubuntu from CD (at least external one).
Ok, I've burned ISO on USB drive.
Installation worked ok, but it turned out that screen brightness is set to max value and there is no way to change it - keyboard switches changes are ignored, software switcher is also ignored.
Reading internet again. It seems some more people had such issues, no definite recipe how to fix this: some people were changing Nvidia drivers (I did that and it did not help, whatever I used and I've tried all of them), some people were updating to newest kernel (also did that and still no luck).
I thought that laptop is broken, but there is some little software called brightness-controller that seems to work (but when I start youtube video, my brightness settings are reset back to max again...). This somehow mitigate issue, but after restart I have to adjust brightness.
Next. Bluetooth. I go to settings, turn it on, GUI shows it is turned on, but it is not. When I move to other settings and back to BT settigns I see it is disabled. So enabling is not working, no error message, no information that something is not working.
Ok, trying to do this from command line. It seems there is some software called rfkill that blocks BT and you need to run rfkill unblock bluetooth to have BT on. WTF???
So, if someone thinks that Linux is working on desktop I have a bad news. It is not. Maybe if you have some 10 years old Intel laptop with graphic card on board, maybe if you install LTS version on Ubuntu or maybe if you install that newest PopOS then you can be lucky.