[destructionator]

> So it being the "age of Terabyte HDDs" does not matter, for packages expected to be installed on a normal desktop system.

But neither does the "size on disk" because the ACTUAL size on disk might be reduced by gzip/bzip2/xz/zstd/whatever is invented later. Even if the program using the package doesn't support compression, it supports filesystems and filesystems often support some kind of transparent compression. It isn't a hard problem to solve.