As several others have already said, public education is the main problem. High schools have been handing diplomas to illiterates since at least 2003, when 80% of all graduates could not read above a 4th grade level.
You can see that here on FR every day, and right here on this thread, with people posting that tires “loose” air...it’s sp[elled “lose”.
Your tires lose air.
Your shoelaces come loose.
And they get indignant when you point it out. But that illiteracy also translates to incompetence. Most cannot understand the requirements of the job, if you hand them a pamphlet with proper procedures printed out, they can’t read it and won’t admit it.
Also, with so many jobs available, many are employed who otherwise would not be, as someone else pointed out.
Tires -
I changed tires for a living once at a western auto store. I found out the pressure listed on the tire is the maximum, not a mandatory requirment.
Watch the tire wear. It takes a few months. If the tire starts to wear in the middle, air pressure is too high. If it wears on the outsides, it’s too low.
My toyota I had then had tires rated at 35psi. They wore evenly at 28psi. At 35, they would wear badly in the middle. I dropped it to 28, it worked great. I just checked it with a penny or 6 inch ruler once a amonth or so.
I keep a small air compressor in the car that plugs into the cigarette lighter. Really handy item.
I go with the vehicle’s pressure recommendation for PSI. As you said, the info on the tire is the maximum of which the tires is safely capable, not the optimum. I do experiment on my cars to get it right. On my motorcycle I go with the bike numbers.
About 30 years ago I picked up a Cadillac air compressor at the wrecking yard for the old air-ride system. Equipped it with a 12v pigtail and used it many a time. Superior to those throwaway plastic ones. Can’t recall the model, might have been Seville. Anyhoo, I carried that in an old mailbag in the trunk for years. Seems to have gotten misplaced in the last move - emptying the trunk & all for moving - but I’ll find it.