it does need some regulating though. the volume of nicotine in the default over the shelf vaping kit... you never get anywhere near to consuming as much as that smoking 20 a day of the strongest brands.
I did the calculation myself and was shocked at how much nicotine was in the liquids, but after looking into it, I believe the nicotine absorption rate from vaping is much lower than from traditional cigarettes[0]:
> Compared to smoking one tobacco cigarette, the EC devices and liquid used in this study delivered one-third to one-fourth the amount of nicotine after 5 minutes of use. New-generation EC devices were more efficient in nicotine delivery, but still delivered nicotine much slower compared to tobacco cigarettes. The use of 18 mg/ml nicotine-concentration liquid probably compromises ECs' effectiveness as smoking substitutes; this study supports the need for higher levels of nicotine-containing liquids (approximately 50 mg/ml) in order to deliver nicotine more effectively and approach the nicotine-delivery profile of tobacco cigarettes.
Whether the amount absorbed is higher I'd be interested to know. I suspect it depends quite strongly on the mechanism (tiny vape pen vs mech setup, how long vapour is held before exhaling, etc).