I don't deny your experience, but it doesn't match mine. I am able to confirm 15 orders over the last two years higher than $50, the highest landing at $73.

Unless we're to believe the app is detecting multiple users surreptitiously and has an opinion on them, group orders / a phone being passed around seems irrelevant, but also not within my personal experience.

(Zip: 94086, and I love Indian leftovers from Ulavacharu, usually individual orders)