Find me someone who vapes who is categorically sure that it has 0% long-term health consequences. You won’t. It is probably a safe bet that breathing in propylene glycol for many years won’t turn out great for your lungs. But all of the evidence to date suggests it is emphatically better than smoking.
If you’re a former smoker struggling with it then vaping is an entirely sensible thing to do. E-cigs will probably save more lives than any other medical intervention in the 21st Century. I’m happy for myself and others to look a bit silly given the above. I couldn’t give 2 fucks what anyone thinks, but it would be sad that people struggling to give up fags went back to it because too many people were like “lol you look like a twat”.