Ember as you guessed, is not for simple apps. So an equivalent set of React libraries would have to do everything that Ember does---even when you are building an app that does not require all those parts.
It's not a fair comparison to talk about a simple mobile-only app, and complain that Ember is too large for bloating the bundle with things you will not use.
> bloating the bundle with things you will not use
The problem isn't that Ember has a lot of things you don't use; it's that the things that are there are much larger than their React counterparts. In terms of actual functionality, Ember doesn't provide anything that React+React Router doesn't. The difference in bundle size arises from the different ways Ember accomplishes the same end goal. This differences make it more suited to desktop apps loaded over high speed internet connections. My point is that as someone who's building PWAs designed to load as quickly as possible, it's unfortunate that Ember isn't even a possible contender due to the minimum bundle size.
- Observable objects and enumerables
- Models with a relationship framework
- Controllers
- A dependency injection framework
- A templating system
In addition the router also provides:
- Parsing of query strings in the router (React-Router does not do that)
- Explicit loading states
- Asynchronous routing
Whereas React-Router + React provides:
- A router
- A view layer
I also don't understand your complaint about PWAs and bundle size. Aren't PWAs supposed to fully cache all the Javascript after the first load so bundle size should be less important? And the competition to a PWA is a downloadable mobile app that's often many dozens of megabytes.
