There wouldn't be an extension because it wouldn't make money.
This is the whole reason behind how Honey works. Honey is using its existence as an extension to steal commission, and partnering with retailers to suppress certain higher value coupons.
HUKD has adverts on its website as one of its means of making money. Something which obviously you couldn't do via an extension or users wouldn't install it.
It seems that the merchants were strong-armed into a mafia-style deal with Honey, in that if they didn't partner with them then Honey would suggest the better coupon codes that not everyone was able to have. If they did partner with them then they would be allowed to suppress those particular coupons. Seems like a damned if you do, damned if you don't situation.
If I were a merchant I'd definitely prefer to have the original affiliates rewarded as they are the ones actually driving the visits rather than Honey stealing the commission after the user is already there intending to buy.
I was thinking the same about why don't they just remove it from the Chrome store, but I'm not sure of the relationship Google and PayPal have.
PayPal is one of the payment methods offered by Google for all kinds of things such as the Play Store, YouTube subscriptions etc. I use it myself for those purposes.
