Career wise? The two metrics that matter is how well liked you are and how valuable you are perceived to be. Actually working hard and being nice can contribute to being well liked at work, and sometimes can increase one's own perceived value to the employer. But being nice and working hard aren't going to be rewarded in themselves.

I'm nice to people because it's the right thing to do. But it also has generally made me well liked my whole life. So I've never had trouble negotiating above-market pay for my jobs.

And I used to work hard when the situation called for it. Which isn't all situations. Most of my jobs had clients or customers, so doing right by them was usually more important to me than doing something right for the employer actually paying my salary.

But I also advocated for myself, made sure that a significant chunk of the "working hard" I did was towards actually documenting my value, or getting recognized for current contributions, and building my reputation for having the right skillsets and problem solving ability for future assignments.

Plus luck always plays a big role. Similarly situated workers at a booming/growing company paying out a bunch of bonuses, versus a failing company choosing which workers to lay off, are going to see very different results even if they're equally perceived. Much of my own success is simple luck of timing, right place/right time type stuff. If I were born 5 years earlier or 5 years later, or simply 500 miles away from my place of birth, I think I would've been struggling a lot more.