Nicotine is the chemical that gets you hooked and there is a reason birds in cities have been observed using them to line their nests to protect against mites.
That's because nicotine--from whence neonicotinoids are derived--is an excellent insecticide. (Unfortunately neonicotinoids also kill beneficial insects, like pollinators, which is why their industrial usage is such a problem.)
Because people who are addicted go for the same hit of nicotine each time, therefore if there is less nicotine in each cigarette they will have to smoke more cigarettes to get their usual hit.
We're talking ~95% drop in nicotine. You'd have to smoke 20 cigarettes in the same amount of time to get the same effect. With the price of smokes these days, no smoke options are going to look a lot more attractive.