I have yet to read a thread on this site where a vaper stopped due to any identifiable side effects. I think moderation is the key. It’s easy to "chain vape" with a new mod, atomiser or juice as one tends to want to give it a quick good test. Also, you will notice with vaping, people tend to have a few deep quick draws in short succession, as opposed to drawing on a cigarette with longer intervals in between draws. This vaping style may cause a heavy spike in nicotine which may cause nausea or cramps.
I must admit, I have also felt a bit ill while vaping, but I know my body: it is from too much in a short space of time.
Lastly, I agree: for me, the biggest side effect from vaping is the massive dent in my banking account and the “addiction” to buying more vape gear.
there have been cases of incorrect labelled juices with much higher nic content (i personally had a mixed up batch) and the most common being people who weren't aware that they suffered from PG allergies.
apart from a few isolated incidents, none that caused vapers to quit completely.