Perhaps he is happy. In my personal experience, people who aim to tackle these kinds of large problems do so out of an inability to let go and accept life as it is. That's not necessarily a bad thing, but founders tended to be some of the most unhappy and unsettled people I have known in my life, they were just really good at channeling that lack of acceptance into their work and lives.

My hope for anyone who dedicates their lives to this kind of work are able to let go if they reach their deathbed without a solution, because if they can't, that would be a deeply painful way to leave this world.