The first thing that ages in all laptops is the thermal interface material between heatsink(s) and processor(s). Once the TIM begins to dry / age / pump out / degrade, it sets off a positive feedback loop where the chip gets hotter with TIM aging, which in turn gets the chip hotter still and aging the TIM even faster and so on. A little lint and dust in the heatsink will kickstart this even higher.
LCDs didn't have a CCFL backlight prone to aging in a while, and they also mostly avoided OLED so far, so they don't have the other age-prone display technology.
If the laptop is of any value whatsoever, it is built in a way that allows the heatsink / fan to be replaced by a service tech in one hour or less. Most gaming laptops are built that way and many business line models, too. Business laptops have enough spare parts available for cheap, so they win in that regard.
The published MTBF for a part are rarely relevant for laptops and you shouldn't rely on that. Since laptops are carried and used in the full variety of human behavior through the full variety of human environments, their wear levels are varying wildly. For a server HDD, you can assume server room environments with controlled temperature and vibration. For laptops? No way. Some were used stationary in air-conditioned offices, never moved and not even typed directly on them and some were trotted around every day on construction sites in the desert.