I do hope he gets better, but no, not at all do we “need” him. His accomplishments are way overblown and due to his shitty personality he probably alienated more contributors than whatever actual positives he has ever made.
Say what you will about his personality, you don't have to like him but saying that his accomplishments are way overblown is a terrible take. His work flows through every part of the GNU land and it's used by almost every tech person on the planet to some extent.