I’ve bought very dodgy IPA sold in a street market in Malaysia. It was labelled in Chinese as 99% IPA made in Netherlands. It was very oily, either it was rubbing alcohol, or it was contaminated, or who knows what it was.
If you buy from specialzed stores and online, you will get the good stuff, but what about the people who pick it up from a local street market, car boot sale, corner shop, chinomart etc? Lots of people do that, juding by how much stuff those markets sell and the numer of people who regularly shop at places like that instead of “big chain stores” to save money.