People who do anything to get what they want, often without regard for ethical or moral considerations, are commonly referred to as "unscrupulous" or "unprincipled." They may be seen as lacking integrity, conscience, or a sense of fairness in their actions. Other terms used to describe such individuals include "manipulative," "deceptive," "ruthless," or "self-serving."
It's important to note that individuals' behavior can vary, and using these terms should be done with caution, as they can carry strong negative connotations. Some people might resort to extreme measures to achieve their goals due to a variety of reasons, such as ambition, desperation, or a belief that the ends justify the means.
However, consistently engaging in unethical or harmful behavior to achieve personal goals can have negative consequences for both the person employing such tactics and the people they interact with. Society often values honesty, integrity, and empathy, and individuals who prioritize these traits tend to build healthier and more sustainable relationships in the long run.