Why should you?

I mean, it is really handy to have a tool to save you from the initial setup and all that boilerplate code when you already know how it works.

But not knowing how the different pieces fit together will bite you when things start to fail.

Primarily because we're gonna need webpack anyway (using it as build tool in the project) and started before create-react-app started. It's been quite a while but I still don't fully grasp webpack yet.