Last time I was on vacation, and might have bought a pack of cigarettes, I decided "hey, why not try a Juul instead," and, the rest is history.
While I'm overall in favor of vapes and think that they're a valuable cessation device, the problem, for me, is that it's all to easy to vape while I work in my home office - no smell, no fire, etc. I think that makes it a lot easier to continually dose nicotine and really settle into addiction. Also, while I'm sure they're safer than cigarettes, I still have doubts that they're safe, and I can't help but think of the attitudes that used to prevail with regards to tobacco back in the 40s and 50s when I hear folks talking about how totally OK for your body vaping is.