I'm not highly convinced here. While I only fast-read the paper you linked and checked out few references, I found cases of the usual (unintentional or not) confusion between nicotine and tobacco, or where the study population was that of smokers.

It's not controversial to say smoking is bad for you. But that's always been not because of nicotine, but all the other substances you inhale when smoking, some of which are known to interact with nicotine. What's controversial is whether nicotine itself is bad for you, in isolation, and it's of interest to people taking it in the form of chewing gums, or more recently, vaping.

Here's Gwern with a bunch of papers arguing that nicotine isn't more addictive than coffee and doesn't cause cancer, and the whole thing is just confusion: https://www.gwern.net/Nicotine#addictiveness.