I've used Thinkpads consistently for 25-30 years, and still do. I can't really draw a line between "before" and "after" but if I take a long enough period I can definitely see differences in the experience getting watered down or generally worse, from less flexibility to lower reliability.

I still have and regularly use a fully functional X200, somewhere in the box I have a fully functional T42 and an R31 whose only defect is a small screen blemish caused by me closing the lid with something on the keyboard.

But my multiple X1 Gen1 and Gen2 all have various failures (screen, battery, webcam, or keyboard), my T450 has big battery issues, my T470s have screen/GPU and battery issues. T490 is fine for now, X1 Gen11 has crappy battery and is overheating from the get go. These are different generations, different lots and still affected by the same constant issues.