Yes Apple silicon has made it possible to have the device completely passively cooled eliminating the need for a fan, less cooling components which both add weight.Question: does anybody know whether going from Intel chips to Apple Silicon reduces the physical size of the chip and/or the weight? Are these even a factor at all?
To your point about the weight of the microchip itself I doubt the difference is noticeable at all in terms of weight and size of Intel vs Apple Silicon. Since Intel is still using a 10nm process vs Apple current 5nm process there is a difference but then Apple silicon has a bigger GPU and ram integrated into the chip.
But even with all that I doubt there is any meaningful difference.