Building a project
In software development (including video games), the result of taking the source files of our project and converting them into an executable format is called Build. The generated executable files are optimized to get the maximum performance possible. We can't get performance while editing the game due to the changing nature of a project. It would be time-consuming to prepare the assets in their final form while editing the game. Also, the generated files have a difficult-to-read format. They won't have the textures, audios, and source code files just there for the user to look at. They will be formatted in custom file structures, so in a way, it's protected from users stealing them.
Important note
Actually, there are several tools to extract source files from video games, especially from a widely used engine such as Unity. You can extract assets such as textures and 3D models, and there are even programs that extract those assets directly from...