Do you believe that “loneliness is the human condition” is true?

Basically as the title states, some philosophers believe that even though we are surrounded by others, deep down, our internal experience is to feel alone and be in solitude within our subjective experience of the world.

Examples are Jean-Paul Sartre saying that "Hell is other people" in No Exit and Thomas Wolfe saying that "Loneliness is and always has been the central and inevitable experience of every man." Albert Camus and Martin Heidegger also have expressed similar ideas I believe.

I’m just curious to know what people think, if they agree, disagree, and why?