tl;dw:

Affiliate injection: When you click the “Find coupons” button, it will inject their affiliate cookie. This is… somewhat okay in normal circumstances, but they will overwrite other affiliates since they were the “last click.” If you visit via (insert YouTuber)'s sponsorship and use a Honey coupon, it will override theirs and use Honey’s. The YouTuber loses the profit they would’ve made and instead gives it to Paypal/Honey. It will also inject their affiliate cookie if you click find coupons and it doesn’t find any, or if you click okay on their “We didn’t find any coupons, but this is the best deal!” popup, despite them doing 0 work.

Misdirection: They will pop up that they found the “best deal” while intentionally leaving off higher coupon deals, if a company has a partnership with honey, they may for example have a 10% promotion running. With a honey partnership, they may ask Honey only to give users a 5% coupon and say it’s the “best deal” or tell users no coupons are available despite some being available (even if added to their database), so they pay a small affiliate fee to Honey in exchange for lowering the rates they give in coupons so they can still say they are giving them, but using them as little as possible.

Honey Gold cashback: This one, in combination with the above, gives you 1 1-2% of the order, but they make substantially more than they pass to the user anyway. This one is to be expected, but it is just a reminder that they still do normal company scam stuff on top of their notable scammy practices.