30B images isn't that much in the context of Pokemon Go playerbase of ~50 million (conservative estimate based on users today). That's about 600 images per person, in a game that has been out since 2016... that's pretty low adoption as the previous user said. I don't think the quest has been out since 2016, but considering a large fraction of users are basically daily users, it's still quite a small number of images.

That 30B could just be the useful set after cleanup.