It is not true, you see it because people like to brag. But they prefer to hide their problems, sometimes very deep. The society discourages talking about these things unless you are close friends. Whereas positive aspects are amplified.
I give you an example. I have a couple of friends with two kids. They have an amazing FB/Instagram feed. You immediately see a wonderful model family living in a beautiful house, traveling together, enjoying every moment together, all smiling. It seems like they are always having fun in all possible places (it made my other friend who can't have kids a bit depressed).
One day I decided to visit their house and was a bit shocked. The kids were basically terrorizing the family. The father was half-alive but trying to smile all the time, sometimes unsuccessfully. The whole house was very cold because they spent too much on it and couldn't afford heating it adequately. But the most depressing was a bad smell from nearby chimneys of their neighbors. Apparently they couldn't do anything about. For me it was a living hell, I couldn't live in such a place for one day.