Earlier quoted context omitted.
Toilet paper should be measured by volume, not length. Both width and thickness of the sheets can vary. For both, larger is better. All three measurements interact together when forming a wad of paper. All three contribute to the size of the wad.
Density also matters, or you could cheat and sell a roll of paper "fluff". Also, many people fold rather than wad.
This. Mass is just a nonsense unit for me as a folder. You might as well be advertising density or albedo. If anything, I'd want the base unit to be
number of sheets * number of layers per sheet