Taking myself back 30 years, if
vaping had been around I probably would never have become addicted to smoking. That said, I wasn't truly addicted the first 5 years I smoked. Granted I know that you can become addicted much earlier than that, but I don't think most kids who start smoking really think like adults in that the "I really should quit" mantra is running through their heads yet. If it is, then usually they do quit by the time they reach college age.
Sure,
vaping is a great way to kick the habit, but I'm not sure that minors in most cases really have the "habit" part down yet. I do think it's wise to keep minors from being able to easily purchase these, but if it's a choice between vaping and smoking, I would certainly advocate for vaping. I don't believe that nicotine is the hugely addicting force in cigarettes. If it were, I would not have dropped my nic intake by 60% in a year.
There is also the option of, when faced with a teen who wants to rebel, offering a 0 nic solution. I don't see much harm in that. The "coolness" factor would probably wear off pretty quickly and at that point putting it down would be a non-issue.