No Microsoft GamePass. Or none that actually matters, as the only solution is to pay for the higher tier and stream the games - so no game actually runs on the desktop. No, thanks.
Why “no thanks”? I use GamePass with xCloud and it works pretty well on Linux, and it’s a perfectly viable option - unless you’ve got really poor internet, or you’re into competitive FPS games or something that requires ultra-low latency.
NVIDIA support for Linux is far from being on-par with that on Windows, especially the open-source drivers. Is this still true?
Yes. If you’re planning to game on Linux, I’d highly recommend getting an AMD card instead, the AMD open-source drivers are excellent and see frequent improvements - both in terms of features and performance.
Many devices, especially those for gaming, might not have good (or even working) compatibility drivers for Linux. I know my UWQHD monitor works flawlessly on Windows, but requires quite a bit of tinkering on Ubuntu
“Many” -> citation needed. In my experience, depending on the hardware, you may find a better out-of-the-box experience with Linux compared to Windows. For instance, on my ThinkPad Z13, everything worked out-of-the-box on Nobara (Fedora) - including Fn keys, Wi-Fi, accelerated graphics/video drivers… everything. Same with my AMD desktop, didn’t have to install any special drivers or anything. But when I tried to install a fresh copy of Windows on my Z13 (dual-boot), there were almost no drivers - I had to manually install the Wi-Fi drivers first, and then grab the rest of the drivers via Windows Update, which was painful - took like 3 reboots to get everything installed, with long reboot times cause of updates. Painful.
In saying that, I’m surprised that your monitor - of all things - needed tinkering, when they’re usually mostly dumb devices that need no drivers or anything. But then again, it’s Ubuntu so… ¯*(ツ)*/¯. FWIW, I have a fairly recent QHD monitor from AOC and it worked just fine on Nobara, no tinkering required.
The advantages: What else am I not thinking about?
Performance. Thanks to no bloatware like unnecessary background services/Defender/telemetry/Cortana/Bing etc, Linux in general would perform better, at least in theory. YMMV of course, depending on the game/hardware/distro. The good thing is if you use the right distro, or are willing to go the extra mile with tweaking, you can eke out way more performance, such as by using custom gaming-optimised kernels, fstab mount option tweaks and more. Using a gaming-optimised distro means most of these tweaks are built-in, saving you some time.
Arguably, a better gaming-focused experience, when you go for a gaming-focused distro like Nobara, or if you want to go the full mile and make an exclusive gaming box, you could install something like ChimeraOS, which is basically a community Steam OS. Imagine your PC booting straight to Steam, in the fastest possible time, with no distractions like Windows Update, Defender or other nonsense. Basically a console experience, with the power and flexibility of PCs and Linux.
What distro?
Nobara. It’s based on Fedora but optimised for gaming, made by the same guy who makes Proton-GE and Wine-GE (GloriousEggroll), so you know it’s the good stuff. Obviously comes with ProtonGE/Steam/Lutris etc out-of-the-box, custom kernel, patched Discord, codecs, nVidia drivers and more. Definitely give it a go if you’re considering Linux for gaming.