Health wise, they are a step up from tobacco.
Does that mean they are good for you? No. But, if you are addicted to cigarettes, a less harmful substitute is a good thing.
This was on another site for a smoker who was no longer allowed to smoke in her apartment:
I’d like to teach the world to vape in perfect harmony
I smoked heavily for years. Bought a vaporizer, never looked back. I mean, I looked back, but the point is that I’ve not smoked (tobacco) since. Not even a puff. Ciggies still smell nice, and I often think I’d like one, but I have no ‘craving’ - vaping gives me nicotine and the same physical action. Smokers can probably relate to smoking ultra lights; basic vaping gives a similar feeling, but tastes nice, smells nice, and doesn’t involve inhaling smoke. Also, it’s cheaper: $30 will give her a basic setup; after that it’s a couple bucks a day for commercial liquid, or pennies (well, dimes) a day for (far superior) diy.
I’m not a fan of pressuring people to quit - any time someone pressured me, I lit up. Still, she could use one at home while smoking elsewhere, and it would be easy to quit ciggies entirely after that, if she so chose.