Because many smokers, probably in the millions, have successfully used vapes to quit smoking.
I would guess all this is propaganda to try to ban vapes but keep cigarettes legal. UK's NHS actually promotes vaping as a smoking cessation as policy.
Here's the NHS page on e-cigarettes. You don't see the constant fear mongering you get from the US. I wonder why.
https://www.nhs.uk/live-well/quit-smoking/using-e-cigarettes...
There is a financial incentive in the US for the government to do this based on the tobacco master settlement agreement in which the tobacco companies give the states money based on smoking rates. Lower smoking rates, less money in the budgets. Ban the most successful smoking cessation tool, get more money when people go back to smoking.
https://en.wikipedia.org/wiki/Tobacco_Master_Settlement_Agre...
Edit: Source: 19% of people who used vapes to quit smoking still weren't smoking after a year. This compares to 9% for other cessation products. It's the most successful cessation product by more than double.
https://www.webmd.com/connect-to-care/vaping/vaping-smoking-...
In 2019, there were approximately 50.6 million smokers, so it would be pretty easy to say at least a million people quit smoking using vapes with a 19% success rate.
https://pubmed.ncbi.nlm.nih.gov/33211681/
In 2022, there are nearly 40 million smokers, so in 3 years, over 10 million people quit. If just 10% of those who quit used vapes, that's a million.
https://www.cdc.gov/tobacco/data_statistics/index.htm
Unfortunately for me, I'm one of the people who quit smoking using Juul. As soon as they are banned, I will most likely go back to smoking. I wish that wasn't the case, but it probably will be. Bad for me, bad for you, great for state budgets.