The wrongful appropriation or stealing of anothers language, thoughts, ideas, or expressions (i.e. intellectual property) and the subsequent representation of them as one’s own original work is considered deceitful.
In the case of written documents this is called plagerism and is considered academic dishonesty and a breach of journalistic ethics. In the case of patents or copyrights the practice is illegal.
Copying
Copying others work with permission and attribution can be effective reducing your time of rework (i.e., doing something yourself that others of have already been done ).
Automation is founded on this very principle. The first time something is created or processes can involve significant time and effort.
Once the “how” has been figured out, replicating the process can be much faster, take less effort and provide consistent and sustainable quality.
Exercise Caution
While imitation can be a form of flattery for the originator without acknowledgement of their role it is a form of theft. Replicating others efforts can be useful and effective, but misused can have significant negative impacts.
People can be upset if you use their ideas or outcomes, particulary if it’s at your benefit and their expense. However, if all benefit it can be a win/ win situation.
So re-using the output of other people can be a way to work harder, not harder. It can also be viewed in very negative ways with serious undesirable consequences, unless proper permissioning and attribution have occured.