We are all human and all humans face the same trauma, challenges and health issues. Mental health doesn't give a fuck how much money you make or how many followers you have on whatever social media site. There are people struggling all over the world and there is usually no way to tell who they are. In person they often seem like the happiest person alive but in private they are sinking into a bottomless pit of despair.
What you perceive about a person can be dramatically different from how they perceive themselves. It is often the grass is greener folly. I would guess a good percentage of the people here on SS have a view of themselves that is far removed from reality. I have seen some amazingly talented and beautiful people here who thought they were talentless and ugly. If you tell them any differently, they are only going to assume you are simply being nice and not sincere.