Sandboxing through virtual machines offers an isolated environment where developers can run and test software on different operating systems without affecting their primary work environment. This isolation helps in preventing potential software conflicts or system instability that could arise from direct installations on the workstation's operating system. Other options like VDI or Application virtualization do not exactly fit this use case, as VDI often refers to managed desktop environments provided by the IT department, and application virtualization typically decouples applications from the OS to be run in portable, managed units rather than providing full OS environments for testing.