I've seen this a lot more in countries where internet access wasn't too common until the past 5-10 years and people didn't start out with a less centralized web before apps and closed networks gained popularity.
My partner isn't from the US originally and when I mention how obnoxious it is that Facebook is like the new AOL and I thought we were past this, she reminds me that it's all anyone back home uses for anything and they didn't have internet access back then.
To her and her friends/family back home, the internet basically is Facebook (and occasionally being forced to open their browser app to search for something if they don't just ask around on Facebook). A handful of other apps and defaults define the internet for them and anything else just sounds like too much hassle.
What I mean is that we are comparing two different beasts, so I'm not sure "it happened to MySpace" is a good telltale sign of what will eventually happen to Facebook.