Wow. I'm drawn between thinking "what a mess" and not really seeing a way to substantially improve it.
I mean, it wouldn't be particularly challenging to design a neat unit to charge umpty AA and AAA batteries, while providing oodles of USB power, from a single mains plug. But it would be untested, a single point of failure and probably not a substantial saving on weight/bulk.
And cables are cables. They're going to fail at the strain relief, the question is when... I'm not sure that pre-emptive replacement would be worthwhile. Carrying a spare probably isn't either, at least for the USB ones, which are fairly ubiquitous.