They are just as bad as regular cigarettes, possibly worse, and yet people perceive them as less bad, causing overconsumption.
I have known many menthol smokers and have spent most of my life around smokers. I have literally never once heard the opinion menthol was somehow safer. In fact, I have often heard the opposite; with claims that the menthols have "fiber glass" in them.
“Menthol makes it seem less harsh, and also makes the body absorb more nicotine,” she said. “That means it’s easier to start smoking and harder to quit.”
So not more dangerous per se, but it mitigates barriers to its consumption.
Whether there’s data to show that these effects are significant enough to justify a ban specifically on menthols, however, I don’t know.