The affiliate networks (CJ, Impact, etc) are the ones who determine what attribution method to use, shopping extensions just comply. The vast majority of shopping sessions don't have any prior attribution and merchants fund all of these commissions (nothing is taken from a creator or a user). Yeah, it does seem like the codes Honey has have gotten worse in recent years, probably just a consequence of PayPal acquiring them and not giving it any attention (and layoffs). But the example MegaLag points out of finding a better code on a coupon website DOES THE SAME THING AS HONEY (overides the attribution).
So are there some problems with the affiliate industry? Probably. But calling Honey a "scam" seems completely unfair and lacks critical thinking. It's saved me thousands of dollars over the years.