They aint. Place i worked at years ago put them in a bunch of trucks to apease the drivers. Most were broken and replaced after about a year or two. They used a few diffrent brands too and none of them save a handful of the expensive "semi style" top end ones held up.
Plush isn’t always a good plan. Especially in a truck seat
I’ve had some plushier type seats and after 3 hours I would start shifting around
I have had a Minimizer long haul seat for the past 4 years. At first it seemed too stiff but I can drive all day with little if any discomfort