Pacman has fucked me so many times, I will likely never use Arch again. rpm-ostree has always had my back.
No, major OS releases used to cost money for a license. The same way a Windows 11 license costs money. Apple stopped charging for OS releases but Microsoft still does.
Only the optical sensors do this. The newer ultrasonic fingerprint sensors are more accurate and don't require any light/brightness changes.
I recommend going to a closer store.