I don't think vaping has peaked at all but to me, the focus seems to have changed. I've been vaping since 2009 so I have witnessed the incredible growth in the industry from new technology to a gazillion new vape stores.
Nowadays though there seems to be more emphasis on chasing clouds and pushing batteries to their max than anything else. For example, there are a shitload of juice vendors that I can't patronize because they cater specifically to the cloud chasers by ONLY selling all or high vg juice only in strengths 8mg or less. Juice made to make your clouds more dense with little to no kick does nothing for my nicotine jones. I vape 24mg, finally down from 36mg, with a preference for at least 70% pg and every puff is inhaled deeply. Now don't get me wrong because I have chased a cloud or 10 in my day, but those cloud chases are simply for show because they don't satisfy my craving. They do look sick though.
Overall imho, vaping is here to stay and is just hitting its stride which is why big tobacco is trying to get in on it. My .02.