The counterfeiters buy legit products and return their cheapo fakes through fake buyer accounts. So for the price of manufactoring the counterfeit products they’ve purchased the real thing.
They then sell the authentic products through other channels and appear to be supplying authentic, quality products affordably to buyers and marketplaces while at the same time poisoning the legitimate market.
It’s essentially counterfeit laundering.
Most of the new ones have zero sugar. The sugary ones cause people to crash after using them, so the newer ones all have sucralose for sweetener.