Hard work pays off, but not necessarily in the workplace. The biggest downside is that even when you put in a lot of effort and get things done, there may not be much reward. It may even bring some hostility from colleagues, causing imbalance in your mindset and leading to irrational decisions.
For example, in a company where you are clearly doing well and achieving results, the praise from others in the team goes directly to the boss. However, the boss doesn't seem to be happy about it. Instead, there is more hostility from colleagues in the team. Maybe it's because they have a higher position but haven't done much. As frustrations accumulate, your mindset becomes negative, and you decide to quit and look for opportunities. But those so-called opportunities are not really opportunities, just impulsive decisions. And all the difficulties that follow stem from that decision.
The lesson here is to stay calm and consider the cost-effectiveness, rather than focusing on emotions.
There are also many examples where hard work pays off. One person's output in terms of KPI far exceeds anyone else in the team. Most of the difficult problems in the team are supported by me. However, the boss is still not happy because doing more work also increases the probability of making small mistakes. I don't know what my boss's boss and my boss specifically say, but every time they say that his boss says I'm not good enough.
Continuously burying yourself in work and striving hard may lead you to realize that the more you progress, the narrower the path becomes. Some skills become surplus while others are greatly lacking, and in the end, you become capable of only doing certain things.
As a worker, you should consider the cost-effectiveness, the actual income compared to the investment.