Employees who work more than the absolute bare minimum not only make things harder for everyone including themselves, they also undermine the entire job market.
An employee that works hard and delivers, sets high expectations for both himself and his colleagues. Corporations demand constant growth so if you put x amount of effort, the next year they want you to put 20% more. So you are undermining yourself by doing so. You are also ruining the work environment for all your colleagues because the employer now expects the same if not more from them.
However, here’s what makes it even worse. Since you work more and you’re more efficient at what you do, your job can now layoff more employees and push the responsibilities they had onto you. And they do, do that. This dynamic destroys the job market for all those unemployed and seeking a job because companies don’t need them as much anymore, they’ve successfully allocated more responsibilities and work onto the current employees.
In a capitalist system, you need to learn to adopt the spirit of capitalism by making the most money you can with the least effort possible, even at the cost of seeming dumb and lazy. Our politicians and corporate masters are idiots and lazy yet they profit so much from the system and they don’t give two shits that you can see how stupid they are.