There's also the job someone else is unable to do.

doing something someone else can't do

Sometimes it is doing something nobody else can do

My workplace has heaps of cool jobs. No one person can do them all. So we have more people, doing cool jobs. The world is not all doom and gloom.

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.

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

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

If you're not spending your employment trying to do what you want to do vs what your boss wants you to do... What are you even doing with your life!?

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

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.

If that were the case, there wouldn't be an application and interview process.

There are often multiple candidates for a given position.

Edit: I read this as "no one" rather than "someone."

I understand that someone on earth might not want any given job.

(Edit: Looks like... my Firefox is blocking this image from just loading (it thinks it's a "tracker", I guess... which maybe it is) even though it's a valid image tag. Not sure how many viewers are affected. I'll just link to the image instead.)

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