Task runners like Grunt and Gulp can automate workflows like compiling, standardizing, mapping and minifying code. They can also handle tasks like linting, debugging, error handling, unit testing, live browser updating and aiding in production deployment. Using a task runner can save significant time when starting new projects by automating common setup and installation tasks in just a few seconds versus manual configuration. Common JavaScript task runners each have pros and cons for different use cases and levels of experience. It's best to leverage existing starter templates and boilerplates online rather than building workflows from scratch. Caveats include ensuring compatibility when collaborating or across different machines.