Why doesn't somebody(manufacturers) reverse thread the left side of (don't know what they're called) for lack of knowledge, the axel, so you don't lose the retaining nut at high speeds?? Bicycle manufacturers figured it out for the pedals and cranks

There are custom axles and such that have that, but yeah it would be helpful.Though if you use locktite you should be fine.

If you ever have wheel nuts or hexes come loose, locktite blue is the way to go. Alternatively, for stuff like stadium trucks and short course trucks that use a simple nut on an axle stud, nyloc nuts work superbly as well and do not need locktite for awhile. None of my trucks have LH threads on the left side of the trucks, but once I used locktite, I never have loose wheel nuts now. Usually only need to treat the nuts to locktite once or twice a year.

LH threaded axle shafts is a novel idea, but would increase the manufacturing costs and thus the end user cost. Some would pay extra, some others may not?

If they used left hand thread for two wheel nuts/axles there would be a price increase for parts and cars...and a multitude of forum posts asking " why will this nut not undo"? There are so many ways to keep your nuts tight....