For us, more capable just means:yep, but aluminium or steel makes no difference, all the independent suspensions need a bit more reinforcing than a solid axle leaf sprung suspension.... which adds weight and reduces payload capacity.
The "more capable" comment is subjective. Solid axles and leaf springs are well proven thru every war. Independent reduces unsprung weight... Definitely an advantage for handling in a sports car or ride in a luxury car but in a trailer..... not as important. It is definitely hard to measure any advantage in an expo trailer given the extra cost. .
Ability to raise, lower, and level the trailer.
Ability to crawl through deeper arroyos without dragging or bending the frame.
Ability to go through washboard and other bumpy roads (including "paved") without rattling the trailer apart inside and outside.
Maybe there are solid axles and leaf springs that can do all that at rock bottom prices in comparison to the independent suspensions? I don't know.