For me, using Windows 2015 LTSB is the most important and challenging requirement to get a modern laptop to be comfortable. I have been successful in finding workarounds for driver issues, but with Intel 10th gen (400 series chipset), there are some issues. The 400 series chipset requires 17.x intel RST drivers, which frequently BSOD on 2015 LTSB (at least using modern intel chipsets). The last working RST driver on these Dell laptops I have been testing for 2015 LTSB is 16.x, but it only supports up to 300 series chipset. Also, it is very difficult to get the sound working properly, due to "Intel Sound Technology" drivers.
XPS 15 7590, which uses 9th gen intel (and 300 series chipset), I was able to get everything functioning optimally (unfortunately, it uses PWM below 26% brightness, which is very bright). I bet an XPS 13 9380 would be the last usable XPS 13 version. The matte FHD on the pre-2020 XPS 7390 and earlier (although 7390 doesn't run 2015 LTSB properly, which is why 9380 should be optimal) doesn't use PWM. New XPS 13 with 13.4" screen and 16:10 aspect ratio has PWM.
On Inspiron 13 7391 2-in-1, there is the BSOD issue from intel RST, and while Realtek driver is installed, it does not appear to be receiving sound due to malfunction in the intel sound technology OED driver (which has to be forced to install by removing build requirements in driver ini).
I think modern windows 10 is what is behind a lot of modern windows laptop discomfort. 8th and 9th gen intel might be the last properly working systems on 2015 LTSB (and thus also build 1507/1511). No idea about AMD-based laptops.
Experimenting with an XPS 13 7390 now, but it has the 400 series chipset.
Disabling the intel graphics and switching to Microsoft Basic Display adapter (it is adequate for web browsing and Microsoft office) is the other piece of the puzzle to make modern laptop usable, but it won't eliminate the discomfort of newer windows builds, it has to be done in combination with 2015 LTSB/ 1511/ 1507.