Neither you nor I can say with 100% certainty it does or doesn't. They didn't go deep on their hardware that I saw. All I was pointing out was that that was a bit much of a simplification. There are reasons to look at the kernel. Just not a lot of them. Largely I agree with you though. Debian, fedora, or any of their offshoots on hardware from the last ten years potato potato right?
But on a potato. I have an old laptop with a core 2 duo in it. A late 2000's laptop that only ran windows 7 at best. It's still surprisingly capable despite its age. Put something like a modern fedora on it, though that's a different story. It becomes slow almost to the point of being frustrating to use. No matter which desktop environment I'm using. Drop MX or similar and it's a whole different experience. Part of it kernel patches, part of it run times. Even i3/i5/i7 haswell or older can see a solid boost on kernels not compiled with modern processor extensions primarily in mind.