One thing I'd add is that downloading zip files is not as popular as it once was, due to hidden malware or similar, and some downloads might get blocked.
If you need to use the zip file to control a directory structure on download, or it's essential for compression, then fine.
But if it's a single file and the compression is not large then just offer the original file. I've seen people offer single pdf files in zips with little compression benefit and it just unnecessarily complicates things for the end user.
Hope this helps,