Average lifespan of a (Lenovo) laptop PC?

I know there are a few gearheads on these forums, and plenty of regular PC and console users as well, so I wanted to pitch the question: what is (and/or what should be) the average lifespan for a gaming laptop PC? Say, a mid-range Legion, for example?

This answer probably varies a lot depending on how high-end and new the GPU is when the laptop is purchased, so I'm really looking for personal experiences. I'll start with my own...

Around 3 and a half years ago, I bought my current laptop, which is a Legion Y540 with an RTX 2060. The model is actually discontinued now (so I guess that shows how quickly things go out of date), and the GPU is ancient by the newest standards, but in my humble opinion, I don't think 3 and a half years is really that long.

I got the laptop on a sweet deal, and when it first arrived, it ran everything at pretty much the highest settings with no issues. Now, it skips and lags on games that should be shockingly easy to run. My guess is that I wore it down without taking care of proper cooling and constantly leaving it plugged in, but should it be considered on the lower end of equipment these days?

Fine with brutal feedback because I know my specs suck, but please do share how long your machines have lasted and how long you think they should!