People commonly talk about Minimum Viable Product (MVP), but we also have the concept of Minimum Viable Team (MVT). The MVT is the smallest team possible to achieve your purpose. One common purpose is, of course, building an MVP.
In some cases, the MVT is one person. That's ideal when the situation permits. Many companies get started this way: one person who can keep every aspect of the vision and all practical details in their mind, who can execute everything required for the first stages of a new company.
In established companies, most people's skills are specialized. An individual may wear multiple hats, but they don't wear every hat. For larger projects such as conceiving, architecting, building, marketing, and launching a new product, it's uncommon to have one person who can do this. However, individual aspects of a project can be broken down into the smallest pieces possible where overlap is minimized.
A complicating factor of the MVT can be time constraints. Parallelizing development can speed up completion of a project even if total efficiency and quality are reduced.
One area we strive for a team of one is on the software side of a new project. At a project's earliest stages, there are so many decisions required and such rapid change that trying to coordinate between developers is wasteful and leads to inferior design. Instead, we empower a single, experienced developer who can leverage others for architectural input when desired. When that developer is ready for more hands in the code, we bring them in.