It’s definitely a positive outcome when it comes to cancer prevention. The evidence is quite clear that vaping is way better than smoking for lung cancer. [0][1]

I think the evidence is out as to what, if any, are the harms of vaping. But it’s not arguable that it’s better for you than smoking.

[0] https://www.newscientist.com/article/2120440-switching-from-...

[1] https://pubmed.ncbi.nlm.nih.gov/28778971/