I had to have at least 6.12 to have drivers for all my hardware, and Debian is even now still only on 6.11. I'm using 6.14 now because that's the newest that will work without making other changes, and I've been uninterested in figuring it out as this is new enough for my purposes otherwise.
Back in times of yore it was normal to build your own kernel, and today Debian and Linux together make it very easy once you get through the long-winded documentation, as the files you need to make the debs are in the kernel sources. Especially if you are willing to go version by minor version, but often even if you want to skip a number of them, you can usually just make oldconfig and hold down enter...