Ask HN: What all does React leave on the table?

Could I get some clarification on React? Basically, it works as the V in your classic MV* framework e.g. Angular. Ok, I understand that, but where does React fall into play when it comes to building an actual app? In other words, what all is being left on the table when using React instead of something like Angular.

What I am trying to figure out is what other libraries do I need to learn if I focus on React instead of Angular. For example, let's say I want to build an app using the mean stack, but I don't want to use Angular. In that case I need to switch out Angular with React + what else?