Who takes the cap off the bottle to smell it and thinks Yeah! that's sure to catch?
I'm not sure what percentage of additives sold to anglers are artificial, but chances are, many haven't even tried the real thing, its no wonder some say they don't work.
By the real thing I mean an extract not a flavour.
The difference is huge.
Fish can become accustomed to that 'false' chemical smell and home in on the baited area, but they can also spook. Most Humans can't tell the difference and anglers often add a bit extra for luck, inadvertently masking the natural smell of bait and ruining their chances. In short, Flavours cover up and ****** up amino acids and enzymes which fish find attractive.
Flavours are just that, flavours. They're NOT real, they're artificial and most of them attract anglers more than they attract fish. Only an alcohol-free extract is real, can't be overdosed, smell and taste natural (because they are), won't blow or spook fish like artificial (man-made) flavours and they work everywhere, all-year-round.
Flavours are a waste of money.