If more people would work those jobs, each would have to do less of it

I specifically mean those companies that do not directly add to the jobs that “need” to be done.

My feeling is that more people work bullshit jobs because they pay better than e.g. harvesting crops or driving a bus.

True, but how many people actually work to make that happen?

Most people I know work for a company that works for a company to increase the profit of another company.