We know round wheels work, so why would anyone do what that oft-used cliché says you should not do and reinvent the wheel?
Because that's math, it doesn't have to be real. Math is a language so mathematicians can travel through time and make me invisible too - just like science fiction writers can. That doesn't mean they will.
But when it comes to rolling, Steve Mould at Numberphile shows you actually can use a non-round wheel. And they can even use a triangle, showing they are far more awesome than me.