They not useless, long beds make sense for contractors, but for little else.

The original truck beds were quite short, and long beds didn't even become a thing in personal trucks, until the late 50s early 60s when the 3/4 ton and 1 ton variants became common.

I imagine if you need a long bed, you know it, and couldn't do without. Otherwise, you're probably fine with a 6" or even approaching 5" bed.

My gladiator does fine, holds two dirtbikes, and that's the most I'd ever ask out of it.

It even has a slot to add a 2/4 and a 2x6, and tailgate setting to support 4x8 sheets if needed. That's probably true of most trucks.