I'd like to add to morgante's excellent comment: You don't need any of these things, but they make it so much nicer and easier to write an application. You can

I'd like to add to morgante's excellent comment: You don't need any of these things, but they make it so much nicer and easier to write an application. You can easily write a React app without them, but it's less fun and it takes more time. The point of the boilerplate is to let you focus on writing your application, and let the boilerplate take care of making that experience a very nice one.