They’ve taken up space for quite some time now, just so very little, You have to have like 200 aspirin before the aspirin stack volume hits 1. You can get away with stacks of 199. They count as volume 0.
They even have weight, too. But unlike volume, fractions of weight are combined and calculated.
I may have at one point criticized how the game lacks decimals to show the exact weights and volumes for pills and powders and other such low-weight items, even in item descriptions, but it’s not a huge deal for me.