Someone who is good at everything they do is often referred to as a "polymath" or a "Renaissance person."
Polymath: A polymath is a person with expertise in multiple, diverse fields of knowledge. They excel in various areas and have a wide range of skills and talents.
Renaissance person: This term is derived from the Renaissance period, which was characterized by a great emphasis on humanism, art, science, and learning. A Renaissance person is similarly well-rounded, excelling in multiple disciplines and displaying a thirst for knowledge and creativity.
It's important to note that while these terms describe individuals with exceptional skills and knowledge across various domains, it's rare for someone to be truly good at absolutely everything. In reality, most people have their strengths and weaknesses, and being a true polymath or Renaissance person is an extraordinary and rare characteristic.