Yes, I used to think exactly the same thing, DB is most definitely a weird bubble, but then as an expat every area of HK is a different kind of weird bubble, be that Mid-levels, Central, Peak, TST, Stanley etc. In fact HK as a whole is a pretty weird bubble in Asia.
When I first visited DB i thought it had strange Stepford Wives/Truman Show/artificial vibes. So we initially dismissed it as a place to live.
But we realised it holds many attractions that make it ideal especially if you have a young kid or two. We ended up living there very happily for three years and would highly recommend it for many different types of people (but especially young families, as mentioned).
Is it actually your friend who moved to DB, but you'll download the app?
I'm just, ya know...asking for a friend