Wheels and axles did not come from existing biology, unless you are being pedantic. Wheels for locomotion simply was not a viable strategy for evolutionary driven organisms due to their reliance on infrastructure. Why expend valuable energy to build and maintain roads when it helps your competitors? If animals moved with wheels and built roads, the laziest ones benefit the most, and as more and more organisms get lazy, they gotta switch to another method.
I don't think we should worship biology like it's some miracle process with infinite wisdom. It makes sense to look to nature and biology for solutions when the engineering parameters are aligned (see wood, an excellent material that has impressive properties.) Otherwise, a lot of things that we retrospectively attribute to being inspired by nature are merely convergent designs (there aren't many ways to make something aerodynamic, if you would be surprised)
EDIT: I misread your post and I thought you were saying that wheels and axle were from biology. Sorry about that.
The free-rider problem isn't necessarily the dead-knell for biological infrastructure.
Ants and bees build hives after all. Trees build, well, trees.
It's just that for biological systems, it's relatively easier to build legs than wheels. And as you suggest, wheels need more infrastructure to be really useful. So even if you could solve the free-rider problem completely (which you can't), it would still cost biological systems more.
> Ants and bees build hives after all. Trees build, well, trees.
Yeah but those ants or bees are not competitors with each other, neither are cells in a tree. All organism you described have a strong separation between reproductive parts and the ones which build infrastructure.
Similarly to how the cells in your bones and muscles don't reproduce.
This is one of the ways biology can work. And it's not in contradiction to what I wrote. Just the opposite.
Though to go a bit deeper: plenty of other creatures derive advantages (and disadvantages) from trees. But for making the biology work, the advantages to the tree genes just have to outweigh the disadvantages to the tree genes.
Below a certain size, propellers are less efficient. It's a fluid dynamics thing. I learned about this from a colleague flying robots inspired by insects. If you find an article about bee flight dynamics that's not BS (creationists still sometimes try to use bumblebees as an example of divine magic), it may also explain it. The short version is that with a small propeller all the air around it just starts spinning.
I don't think we should worship biology like it's some miracle process with infinite wisdom. It makes sense to look to nature and biology for solutions when the engineering parameters are aligned (see wood, an excellent material that has impressive properties.) Otherwise, a lot of things that we retrospectively attribute to being inspired by nature are merely convergent designs (there aren't many ways to make something aerodynamic, if you would be surprised)
EDIT: I misread your post and I thought you were saying that wheels and axle were from biology. Sorry about that.