Interesting idea.

Other implementations I like...

In Solasta, you unlock a guild that will scour a battlefield after battle for all the junk items, haul it back to town, and sell it for you (taking a small percentage cut for their troubles).

In Rogue Trader (which I've just started playing before Helldivers 2 got a squid invasion), you're tooling around the 'verse in your trade ship. So its only natural that while looting you can opt to crate up anything your party doesn't need as trade fodder. And in fact, that gear can go towards creating (forget the term) lots / pallets of a certain trade commodity types that's used during your economic activity.

@Paul Hosking Yeah, going around in a ship or boat or something also has a certain romantic adventure appeal also.

I just bring up the possibility of a pack animal because it's not just a vehicle - it's a sort of friend also.

But of course, you can have both! Besides the obvious possibility of a ship large enough to carry a pack animal, a pack animal can tow a river boat.

Plus, you can eat a pack animal, if things get dire.

@Digital Luddite Yeah, that's appropriate if your game is designed to be set in a pretty harsh environment (or you need to visit harsh environments to progress in the game).