Evan Carmichael argues that work tied to helping others changes your energy and motivation in ways that purely self-focused work cannot. A life of meaningless work leads to unhappiness and depression, while purpose-driven work provides the power to wake up feeling like what you do matters.
Chapters
If you woke up every day and felt like you don't matter and you're driving to a job that you hate and nobody cares if you show up or not or give your best and you're doing work that is meaningless, if that was what you were doing every day, which I think is most people, then that's the path to unhappiness and stress and sadness and depression and suicide because you feel like you don't matter. But if you woke up every day and felt like this might matter, what I'm doing today might matter to somebody, if you felt like today was going to matter, you show up with a completely completely different energy. And so it's not enough to do something for yourself. When you can tie it to this is going to help somebody else out, you have so much more power and motivation. And I think that's what leads to long-term happiness through fulfillment.