Here's a reason that works for me: if you don't accept happiness, you're contradicting yourself. But I suspect most people can't sort themselves out that easily... #maybe
The allure of work at the civilisational level is not attractive, because I presume nothing special in myself. I have the long-term view that civilisation will figure out certain systematically limited problems, eventually, in its own time, whether it takes 10 years or a 1,000. This is why I think of my studies in machine intelligence and the quantification of consciousness as "hobbys" not as "missions."
The allure of work at the commercial level is even less attractive, because of the weakness it implies - that one cannot be happy without external goods and services that have yet to be bought. (See initial point above.) So I find it pretty difficult to empathise with people who are motivated in this way...
All that really remains is to entertain oneself. E.g. "I see you are in pain, I feel your pain, let me help you," or "I see this is a difficult conceptual problem, shall we seek its systematic resolution?" or as I am making myself the game of being interested in plebeian commercial success from 2013-2022, "come let us see where money can be made, for the plain old boring sake of aiming for higher numbers."