Ahh, but the difference here is not in the stability of Debian vs Ubuntu, but rather the fact that Debian's LTS offering is just a community effort, as opposed to Ubuntu having an official LTS release.
Many aren't even aware that Debian has LTS releases in the first place.
I would prefer to use Debian if it was more stable. It worked fine on my workstation but if I try to use it on my laptop it would not ever resume from suspend making it unusable.
I think Ubuntu has the benefit of the large user base making it more likely that your problem is solved.
My laptop is also a 5 year old thinkpad x1 gen 4 so it should be supported, and Debian is the only linux that gave me this problem.
While unlikely, it could've been that the kernel version was too old or you were missing non-free drivers for something?
On my experience, if it worked in Ubuntu, it would work on Debian, and if it didn't, using the latest backported kernel would solve it.
Many aren't even aware that Debian has LTS releases in the first place.