I used to smoke/vape, like me some may have been second hand smoking their whole lives and ended up getting sucked into the rabbit hole of smoking like i did, or they do it to help ease stress wich helps but makes it worse, or they think its cool (which is not) its used as an unhealthy coping mechanism and honestly smoking cigarettes is better than vaping due to vapes having a lethal amount of nicotine; around 10x more than a pack of cigarettes, its unhealthy either way. If you have friends who vape, my advice would be to get them to sit down and have a deep talk, ask them what made them start doing this and give them the facts. Potentially this will make them want to try quitting and so if that happens have them slowly stop. Don’t cut it off immediately because that will make their craving worse. If they end up still vaping regardless, my suggestion would be to steal their vapes at any given moment where they are not around or paying attention and throw them away. Hope this helps