[fuzzfactor]

>an old Windows 10 box feels less laggy than the Thinkpad's fully-patched 25H2

"This is by design" is the excuse so often seen over the decades from Microsoft when the most useful aspect of a feature is just not quite capable of doing the main thing people would really want it to do in the first place. When they want people to quit trying to do what the hardware is obviously capable of. So they don't get more frustrated for "no reason". Lots of times when they put excess effort to curtail brilliant engineering so it could not participate in a launch. The kind of time when you're going to expect excuses.

Surely this is a point when you can logically extrapolate and say "this is by design . . . misguided design."

Oh, well.