Half of all employed adults say they're extremely or very satisfied with their jobs, according to a new report from Pew Research Center, which surveyed more than 5,200 people in October.

Another 38% report feeling somewhat satisfied, while just 12% say they're not satisfied.

But some workers are more likely to be happy than others.

People who are 50 and older, earn an a middle- to upper-income or are self-employed report feeling happier than the average worker.

Among those who don't work for themselves, people are happiest with their relationship with their co-workers, their relationship with their manager, and their commute (among workers who have one).

Workers are unhappy with a lack of remote work and low pay

But a few sore points stick out: A whopping 40% of workers say they're not satisfied with their flexibility to work remotely. Several Fortune 500 companies including Amazon, Citigroup, Walmart and UPS made fresh announcements this year to scale back remote flexibility and require workers to spend more time in offices. The moves have led business experts and workers to question the future of remote and hybrid work.

Close behind is the share of people who are dissatisfied with their opportunities to be promoted at work (38%).

Salary is the No. 3 biggest factor where workers say they're unhappy. Their biggest concerns are that their pay hasn't kept pace with the cost of living (80%), they're being underpaid for the quality (71%) or amount (70%) of work they do, they don't earn enough to pay their bills (54%) or they're paid less than a coworker who does similar work (28%).

Overall, workers are less happy with their work today than in 2023: On seven of the nine items Pew surveyed last year, the share of people who said they were highly satisfied dropped by 3 to 7 percentage points.

For example, while 44% of workers say they were happy with their opportunities for training and development in February 2023, just 37% felt the same way by October 2024.

Most workers say they go above and beyond at work

In addition to drops in satisfaction around promotion opportunities, workers reported less satisfaction with the amount of feedback they get and their employer benefits.

It's a major frustration given most workers feel they're going above and beyond at work. Most workers, 76%, say they do more than what's expected of them in their jobs.

Notably, younger workers from 18 to 29 are most likely to say they do only what's expected of them at work. As more members of Gen Z gain influence in the workplace, they've become known for drawing boundaries around their professional and personal lives, and outright rejecting old ideas around hustle culture.

Looking ahead, 1 in 4 workers say they're likely to look for a new job in the next six months. But they expect significant headwinds: a majority, 52%, believe it will be harder to find a job today compared with their chances in 2022.

Want to make extra money outside of your day job? Sign up for CNBC's online course How to Earn Passive Income Online to learn about common passive income streams, tips to get started and real-life success stories.

Sign up for CNBC Make It's newsletter to get tips and tricks for success at work, with money and in life.