Grow taller.
I can see where the bumper steps on the new GM trucks come in handy.
That said, I can still step up to the bumper and in to the bed. If I'm feeling limber I can from the ground onto the tailgate on my Ram 3500 4x4, but that's quite the stretch.
The DW has to crawl up. I've offered to buy her one of those steps, but she claims she doesn't need one.
My father carries a step ladder in his 3500.