Yes, takeout sort of exists, but it doesn't work. If you sort pictures into albums, you get duplicates of each photo for every album. So one copy in the automatic year album; one copy for each album you have put a photo into. My 80gb of photos triples in size, and oh, sometimes downloads fail on the zips they put them into. And since I use a mac, who has 600gb of free disk to download and extract the zips for my dedup script to run.
Additionally, they intentionally broke their api (well, just disabled it... but only for most users; it seems to still be available for Microsoft) to do incremental backup. tada!
It's the most Apple thing.