There are numbers to back it up, in the study I linked. Is 10 times less not significant?
The primary harm from cigarettes doesn't come from the nicotine, it comes from all the other toxic chemicals released by combustion, which aren't present in the aerosol exhaled from a vape.
Nobody is claiming it to be 100% safe (what is?), but it's not even in the same ballpark of harm as smoking is.