Yeah, though one can imagine that being a billionaire also introduces some problems. For one thing it changes family and friend dynamics and that's really a key source of happiness.
It's the same problem that comes from excelling at anything valued, or having any intensely desired quality. You don't know why people want to be around you, and you don't know whether they will still be there if (or when) you no longer have those qualities deemed so desirable.
Capital is abstracted value that everybody needs. The differences this makes in such a situation is drastically more disorienting.
>and you don't know whether they will still be there if (or when) you no longer have those qualities deemed so desirable
This phenomenon is heartbreaking and surely happens with things like talents and innate characteristics, personality, etc., but it would be very rare with those compared to with capital. When it concerns capital, the issue becomes exponentially more common with exponentially less potential to be understood. When it's happening with more people in a society, it's instances collide and fracture relationships at a far greater rate.
Not disagreeing at all, but "being a billionaire" is a poor articulation of the culprit.
The havoc capitalism plays on social relationships has been documented, researched for centuries. This is the very core of Marxist thought, and to my knowledge has never been contested.
Since you're probably an American and I just referenced Karl Marx, let's please remember Karl Marx was in fact insistent on the importance of democracy (far more than most Americans) and that anyone familiar with his work would have no question of the vast differences between and his well-known disapproval of the Soviet Union defending their project with his work.