Needs citation.
Debian stable uses upstream LTS kernels and I'm not aware of any heavy patching they do on top of that.
Upstream -stable trees are very relaxed in patches they accept and unfortunately they don't get serious testing before being released either (you can see there's a new release in every -stable tree like every week), so that's probably what you've been bit by.
You're right stability comes from testing, not enough testing happens around Linux period, regardless of which branch is being discussed.
It's not easy testing kernels, but the bar is pretty low.
You can do that well enough with Debian's "testing" and "unstable" release channels. Aside from the few months leading up to a new "stable" release, which usually isn't a big deal (and fixing regressions in "stable" should then be a higher priority anyway). Just don't install it on systems that you actually depend on to keep working. But running it on your desktop at home that you only use to play and experiment with is just fine.
Despite the reputations, I've had far fewer issues on Arch-based desktop distros than back when I was rolling Ubuntu and Debian.
That said, Debian on a server every time.
When people switch to arch they typically set things up from scratch, end up choosing simple tools and avoid most of the unstable stuff distros push onto you.
The wiki has more info on this.
https://wiki.debian.org/LTS https://wiki.debian.org/LTS/Team https://wiki.debian.org/LTS/Funding https://wiki.debian.org/LTS/Extended
Whether that qualifies as "heavy" or not is of course a matter of opinion, but it's not nothing.
I’ve thought about (ab)using a Proxmox repository on an otherwise stock Debian system before just for the kernel…
On the other hand, I had and still have many Debian installations, some with Intel integrated graphics. None of them created any problems for a very, very long time. To be honest, I don't remember even any of my Intel iGPU systems crashed.
...and I use Debian for almost two decades, and I have seen tons of GPU problems. I used to write my Xorg.conf files without using man, heh. :)
Maybe you can give Debian another chance.
Debian is great but I can't say this is a shared experience. In particular, I've been bitten by Debian's heavy patching of kernel in Debian stable (specifically, backport regressions in the fast-moving DRM subsystem leading to hard-to-debug crashes), despite Debian releases technically having the "same" kernel for a duration of a release. In contrast, Ubuntu just uses newer kernels and -hwe avoids a lot of patch friction. So I still use Debian VMs but Ubuntu on bare metal. I haven't tried kernel from debian-backports repos though.