Human pulled carts are common, too. I live on a very steep hill, and use a dolly a lot to bring something up. It's a heluva lot easier than carrying stuff. Not even close. I can easily manage 4-5 times the weight on the dolly than I could carry.

Even navigating stairs with a dolly is easier than carrying a heavy weight, and much safer, too.

I'm utterly unconvinced by Jared Diamond's claim that lack of pack animals made the wheel irrelevant.

Oh, and any significant construction site would find it useful to make a road to it, even if they only were carrying things.

Even when barging heavy loads, to get the load off the barge and up to the site a dolly is still highly useful.

I don't believe we even have evidence whether or not the olmec culture had a state. If you're looking for a better narrative, "time" is a decent one. I don't believe there's much evidence of ergonomic hand carts until pretty much modern times. Personally I'm not holding my breath for a decent explanation, ever, especially when the wheel toys are concentrated in an area known for not preserving wood well sans mudslide.

In any case, the baggage cart like you're describing, or maybe a hand truck, seem to be both artifacts coming out of industrialized society. I'm not sure how useful one would be on a steep hill if the cart itself, including the axle and wheels, were made of wood. You don't really see modern, usable baggage carts until the industrialized production of steel (I'd love to be corrected). Hand carts? Sure, but of a more significant weight:load ratio meant for longer distance, heavy load, flat hauling—remember these suckers often have brakes you wouldn't want to engage on a runaway cart, like a peg through the spoke or axle or a wedge under the wheels.

I'd think some kind of carrying + strap frame like you see today would be a better fit for personal hauling and balsa might even work well for it.

> were made of wood

https://en.wikipedia.org/wiki/Ljubljana_Marshes_Wheel

Wheel & axle made of wood, for a two wheel push cart.

Spend some time using an ordinary dolly to move heavy boxes around, then try carrying them. There's just no comparison.

Besides, it's one thing to say that wheel technology is gated by metals technology, quite another to say it is gated by the existence of pack animals.

I’m not quite sure of your point—the cart was obviously found in a swamp and would have been poorly suited to hauling things up “steep hills”. I would at least have used a spoked wheel if I were arguing the obvious need of a handcart, the weight and stability difference over rough terrain is quite large. That, or provided video evidence you want to haul a solid wood cart up a steep hill with groceries.

I’m pointing out projecting modern needs backwards out of speculation isn’t likely to yield much understanding of why someone didn’t invent a handcart in precolumbian mesoamerica. Jared Diamond at least compares the material conditions of the two sets of continents—that seems like a decent tactic for approaching the past, even if I do have large complaints with his confident narratives.

When you're building a stone building, you'll want to be hauling heavy stones. Even a heavy-ish wooden cart would be most helpful with that.

I've been to Chichen-Inza. It's flat.

The Egyptian chariots had wooden wheels and axles, and were light.

https://www.brown.edu/Departments/Joukowsky_Institute/course...

Wow, cool! Thanks for the link.

The axle is also very clearly a turned part, probably made on a lathe.

The Mayans did in fact make roads: https://en.wikipedia.org/wiki/Sacbe

> useful to make a road to it

A rail road even. Dogs and goats are useful for pulling sleds over a rail. Or a trail.

I agree that the size of the animal doesn't makes wheels less worthwhile.