[ng12]

I don't like the "batteries included" metaphor because it implies getting batteries is hard. Yes, Angular ships with routing but thanks to the node ecosystem adding react-router is a one-line command. The hard part is learning the routing API which you have to do either way.

[TAForObvReasons]

"batteries included" means that the software itself has everything you need to get going. It's not that it's hard to get an individual component, but now you're relying on a third party component and potential issues with random configurations etc. It takes some research and effort to figure out that react-router is the best module among the options for routing.