Continuing the discussion from Duplicating microSD cards:
The current Raspbian image, downloaded from here, is compressed, and will expand to over 4 GB. Many compress / uncompress programs can’t handle anything that large because of using 32-bit data and arithmetic. You can do it with 7Zip on Windows, and probably with Unarchiver on the Mac, but you don’t have to. Just feed the compressed file straight into balenaEtcher to flash it onto a microSD card. You will need that USB adapter I mentioned earlier.