Yes the market analogy is not far from reality but it doesn't really explain why the size of the bucket matters but the number, which I totally get why and how the number affects render times, this is the principle under having multiple cores and threads in CPUs and GPUs...
So a better analogy to the market is having more than one hands to hold one basket per hand. Size of baskets doesn't matter because you'll manage to carry the same weight in total and complete the task in the same time by either growing more hands or getting bigger baskets.
But in video (thank you BENTRAJE) it's spot on at the time stamp that what seems to matter is how the CPU receives packets of data compared to the GPU... the rest is specific to the M1 architecture so I didn't watch it all.
So for me, that use only C4D and not RS and thus only the CPU and not the GPU (which also shows in the Task Manager) doesn't really matter as long as I use the same number of buckets as available cores. As long as the speed is maintained the same bicket size doesn't contribute to it, only visually.