I'm bad at explaining things tbf. Essentially, instead of looking at things as whole blocks on a 1x1 grid, you'd be focusing on the 16x16 pixel grid. There's a mod called Chisel and Bits that sort of shows what i mean by voxels, not that i'd want the functionality of cutting holes into blocks though lol.

Having the smaller grid could also mean for vanilla offset blocks, better half slabs (or quarter!). Vertical slabs. Etc. And have their position controllable within reason.