I've not looked at the specifics here - but "stable at X degrees, Y% duty cycle, for Z" years is just another engineering spec.

Intel's basic 285K spec's - https://www.intel.com/content/www/us/en/products/sku/241060/... - say "Max Operating Temperature 105 °C".

So, yes - running the CPU that close to its maximum is really not asking for stability, nor longevity.

No reason to doubt your assertion about gaming laptops - but chip binning is a thing, and the manufacturers of those laptops have every reason to pay Intel a premium for CPU's which test to better values of X, Y, and Z.