>I can buy on the used market a ~2018 laptop with a 15W quad core CPU, 8GB RAM, 256 NVME and 1080p IPS display, that's orders of magnitude more capable..
But it won't be as reliable, mostly motherboards won't last long.
3-5 years for a cheap laptop [0].
3-5 years of office use for a Pi. [1]
Sure, there's other numbers to find as well, but I'd suggest that they're pretty comparable in the way they handle environments. If one would fail, so would the other.
[0] https://pcpatching.com/2025/11/extend-your-pcs-life-how-long...
[1] https://raspberrypicase.com/how-long-does-a-raspberry-pi-las...
Don't know what your source is for that, but that's not my experience, and i've had dozens of laptops through my hands due to my hobby.
The ticking timebomb lemons with reliability or design issues, will just die in the first 2-4 years like clockwork, but if they've already survived 6+ years without any faults, they'll most likely be reliable from then on as well.