Not too surprising. A good rule of thumb is, anything that gives you joy, happiness, or helps with pain & sadness, can be addictive. It can definitely be used as crutch vs. dealing with the underlying issues (such as anxiety).
However, there's a difference between that kind of addiction and chemical addiction which I don't see mentioned in the article. It seems to focus on the crutch aspect, not things like physical ailments from withdrawals and that sort of thing. It's hard to tell.
Generally, moderation should be the key and if you are using it to avoid things that maybe therapy would help with - that's not ideal.
Absolutely right! It can be a pretty great crutch, used sporadically, but constant use signals something else to work on. And depending on the issue, constant use can just make it slightly more comfortable to stay in that crappy state. (Ask me how I know, lol)