If you have a complaint about your styles being so complicated and in a giant 900 line mega file, I don’t see how you address physical size other than breaking up the file.
Granted, nesting support was also added fairly recently in the grand scheme of things, which boggles the mind given how it was such an obvious problem and solution that CSS preprocessing came about to address it.
If modules had existed much earlier it probably would’ve gotten rid of most of the awfulness.