As to the main topic, I disagree with closing rest areas and converting them to truck parking only. IMHO there should still be a couple spots for an automobile drive to use, in case they want to look at a map, check/use their phone, or get a snack and/or caffeinated drink out of their trunk.
I doubt anyone is going to complain if a passenger vehicle stops for 5 or 10 minutes for those things.
For such stops, or restroom-only stops, I prefer rest areas to commercial businesses if they are available and my bladder is cooperating. It's easier to get off and back on the freeway from a rest area, as opposed to exiting the freeway onto an intersecting route, turning into the business and dealing with whatever traffic may be there, and then getting back out onto the surface route and re-entering the freeway.
It's easier to stop at the I-79 rest areas in Lewis County, for example, than it is to get off at US 33/48/119 at Weston and deal with the traffic and the signals at the Sheetz there.