Not just bad to use, but doesn't fully work. I've been trying to get my photos off Google Photos to backup elsewhere, but takeout misses something like 20%-30% of them.

How did you verify that takeout shorted you on 20-30% which is a huge number? This worries me as I've done some takeouts but never fully poked through them.

yes, that is what I meant. Once I tried to download 600GB of photos, and it crashed.