Of course it’s harmful. But its harmful because it’s so easy and compulsive.
It’s genetic.
It has never, ever, been proven to be genetic. It is a habit. It is nothing more, nothing less. It is a learned behavior. How it is learned may be a combination of nature and/or nurture, but even that opens a whole different conversation. But Genetic? No. Like any other habitual behavior, is it something you could easily stop doing for a year? No? It’s a habit. Prove it isn’t more than that by stopping and see if there is a change.