Not necessarily. Zip files have the so-called central directory at the end, indeed, but they have also local directory entries directly before the individual members, so readily available when streaming. For *this* purpose, the central directory is redundant. (At least, when I looked last time, which is nearly 25 years ago.) However, .tar.gz usually has higher compression rates, especially when including lots of small files, because they compress the (tar) stream as a whole, whereas zip compresses individual members, leading to higher overhead. So, yes, .tar.gz would be the better option. And .tar.bz2 and .tar.lz even better.