Well, that’s a separate argument, but is easily resolved.
There is no geometric shape that can symmetrically fill space. You can image that perhaps energy comes in little bubbles, as is proposed by the Quantum Magi, but if that were true, space would have an interesting problem.
Trying to “fill space” has been an intellectual art for millenia. There are shapes, such as a cube, that can be used to completely fill space. But the problem is that if you measure from one cube to the surrounding cubes, you will not be able to get a equal number of cubes at all angles for any given distance (radius). And what that means is that light traveling at one angle would necessarily take longer than at a different angle. And then in addition, which direction would they be aligned?
Three dimensional symmetric space, cannot be filled by ANY shape whatsoever (mathematically proven long ago). Thus to propose that energy itself comes in the form of tiny indivisible bits is to propose that space is not symmetric and also that it has an inherent “up and down”, “right and left”, and “back and front”. Experience tells us otherwise.
So those proposed tiny bits of energy could have no consistent shape. As that shape changed, the size of it changes as well. And there would have to be an infinite variety of such shapes in order to fill a symmetric space. And even then, that space would be grainy. And if you can have an infinite variety of shapes, why can’t you just have an infinitely divisible substance?
The burden of proof is far greater for such a theory than for the theory of an infinitely divisible substance.
And there are other problems, such as “Where did those bits come from?” Somethingness from nothingness?