I like Keanu because he stayed real, even after he reached huge success. He’s just simply not interested in that kind of phenomenon that Hollywood creates for its celebrities.
However, “having everything is having peace of mind”, ok, but don’t forget that to have peace of mind usually requires to have financial stability. You don’t necessarily have to be rich for that, not at all, but when you genuinely don’t worry about money, that gives you a totally different perspective of life.
Some rich and money-oriented people live for the chase, they don’t really care how rich they are. They get obsessed with chasing money because that shows their achievements and successes. It shows they are winning in that field — but in the meantime, they could be pretty miserable in other things, as you mentioned. Just like in Professional Poker, money only shows who’s winning, otherwise, in the aspect of the game itself, it doesn’t matter more than that.
Keanu has chosen to live his life simply this way because he had the opportunity to do so. I think once you reach financial freedom, simple things become more and more interesting to you.