Yes, work is essential for earning a livelihood (in most cases). However, work is not just a means of generating income. There is a reason many of us log into work outside contracted hours, late into the evening or on our days off. Although for comic effect we might describe ourselves as workaholics, I think there is a deeper explanation: public service.
That is not a boastful brag—oh look at me, how pious I am—but an observation on the lengths many of my colleagues and acquaintances go to in their service of others, despite relatively little apparent financial reward. Many people in many roles, regardless of their profession, seem to consider themselves public servants, in the literal sense.
If asked why they do not quit a poorly-paid role in one field, in pursuit of riches in another—or swap one organisation for a company that offers significantly better pay for the same role—they will undoubtedly look back perplexed. Their answer: that their role in life is to serve others.
Many people recognise that beyond satisfying the necessities of life—a roof over your head, food on the table, clothing and warmth, small luxuries—there is no need to pursue an unceasing accumulation of wealth or status. They see that to serve others is the best wealth of all.