It doing something it isn't practical for them to do

What if you’re a professional burglar? Then, you’re doing something other people don’t want to do themselves, nor do they want you to do it either. The society doesn’t need burglars, but some people do it anyway.

Do the job that needs to be done. That is how a lot of businesses get started, keeping an eye out for a need to fill. I used to go to my job and avoid doing work but eventually the boss tracked me down and gives me the shit job nobody wants to do. As I've grown wiser I realized if I take the initiative I can pick the job I want and some other sap gets stuck with the shit job.

Doing something that requires more time than is available to one person.

This is categorically untrue. Jobs exist because one person can't do all the jobs.

I think you've cracked the case. Good job. I'm being serious.

I worked as an Outsource Manager at a couple of game companies (in addition to working for many years as a game artist). I outsourced mostly art asset creation, mostly to cheaper countries. It was kind of bittersweet, since it was clear to me and the artists at our studio that we were outsourcing really enjoyable work, work that our internal artists would rather have done than spend some of their time reviewing the cool art stuff these outsource artists created. But doing this allowed the studio to make a bigger, better game than our limited size team could do on their own.

So basically, I disagree with your premise. There are many sorts of jobs, for many reasons.