The job I have, I would do even if I was rich. Well, that’s only partly true.
I work in aviation in the military, and my job previously consisted of being a flight mechanic doing Search and Rescue, maintaining aircraft, and fixing electronics/avionics on aircraft, and it was awesome, and I’d have done it for free if I could maintain my lifestyle without that paycheck.
The only reason I stopped that stuff and started supervising was because I got too old and broken to continue doing the job I loved, but if you had told me doing this job now (supervising people doing the fun work, occasionally helping them with my arthritis-ridden hands, etc) would be the cost of doing the job I did, I would have accepted it hands down (though in fairness I am looking longingly forward to retirement). And when I do retire, I’ll have to find something else to do for work, because I’ll probably just die of boredom if I don’t.
All that to say, there are plenty of people who don’t work just out of necessity. And like the person in the post, just feeling productive and appreciated does wonders to make it worth more than just the paycheck.