I don't understand what you are proposing to do. If you are able to copy your sdcard data (internal or external) then fine, you have a backup. What apps you use to read it depends on the data type: images, music, ebooks, etc.
You will not be able to copy your apps' internal data that way: they live in /data/data, which is an area that Windows and Mac at least cannot read via MTP (I did manage to mount this via Linux, but that was back when Android supported USB mass storage so no guarantees it's possible now). If USB debugging is enabled then an ADB backup should work, but it's not enabled by default.