In general it's pretty stable. That being said, especially when you're using bleeding edge hardware, it's not perfect.

Take my Radeon 7800 XT as an example. I'm using Linux on my desktop as of January 1st pretty much, and decided I'll go for Fedora as it's pretty up-to-date in terms of kernel releases but also has a great out-of-the-box experience. Kernel 6.6 has been pretty good for me, but newer kernels (6.7.x and 6.8) have issues with my setup. Engaging VRR (variable refresh rate) after the computer wakes up from standby leads to part of the screen flickering white for a few frames every now and then, and eventually the system crashes. Up to 6.7.4 the GPU only output a black screen after standby or even after a warm restart. The latter has been resolved in 6.7.5 but the former issue has not. I've been following a few issues, adding a crash report here and there, trying patch files, but so far to no avail.

This means I'm basically stuck on 6.6 for now, which also means I'm compiling the kernel myself to get the latest patch release, as Fedora doesn't maintain 6.6 anymore.

I had even more issues with Nvidia combined with Wayland. Ironically, Intel Arc probably works the best in terms of stability in my experience.

I'm going to say that in terms of GPU stability, I had a better experience with Windows. Sure, the odd AMD driver release has issues, but Windows does a way better job in recovering from a GPU driver crash. The monolithic nature of Linux means a GPU driver crash will often kill the whole system. I had a case where the system recovered, but in a new desktop session with my running desktop applications orphaned somewhere (basically forcing me to restart). Windows usually just restarts the GPU driver (because it's mostly running in user space, which it isn't in Linux) and you can continue.

I also had an issue with my network adapter (Intel 2.5G onboard) dropping connection after several hours of use. A workaround involved editing boot parameters to prevent PCIe from going into some sort of power saving mode. Searching for the issue revealed that it's likely because how ASUS (mainboard) configured the onboard network adapter.

You'll also need to fiddle with Feral GameMode to properly pin games to the 3D cache cores on a 7950X3D. This is more "set and forget" with Windows Game Bar.

To be honest, Windows is a pretty solid OS from a technical perspective. It has its downsides, but so has Linux. Don't switch for an allegedly technical superior experience. Switch if you don't agree with what Microsoft is doing from a user experience perspective. That's why I switched.

All that being said, Linux at its core is super stable. I use Linux on a few servers for many, many years now, and I don't think I ever had a system crash.