I had to jump through a few hoops to get Linux working right on my XPS 15, and it was actually a major reason I switched to a MacBook. The backlight didn't work with the original kernel released with Debian Bullseye. That got fixed with the next release of Bullseye, but I still only got something like, 4 hours of battery life? I'm almost certain it wasn't properly switching between integrated graphics and the Nvidia GPU, but there are only so many hours in the day to set this stuff up.

I really liked my XPS when I got it, but I'm pretty jaded about Linux support for laptops ever being good enough to compete with something like Apple. And at the end of the day I care a lot more about having a high quality Unix based OS than whether or not that OS is libre (sorry to say).