Comment by MarsIronPI

I've exported my entire photo collection from my iPad. Granted, it was on the smaller side. What I did was select all the photos, upload them to Google Drive, then download the resulting Drive folder onto my laptop. Terribly slow and hacky, and not something you'd want to do regularly, but as a one-off it worked well.

(I was getting rid of the device and simply wanted the entire collection of photos off it.)