Another great thing about ember-cli is that it has very quickly build around it a great community [1]. There are a lot of high quality, well tested addons that are easy to install and use, and it's easy to create your own as well.
The best part about ember-cli is that everyone in the Ember community uses it. No one builds Ember apps without it. The opposite is true of any community/third party React CLI and it's a very powerful difference.
I'd say Webpack plays that role in the React community, just without a blessed and shared way to configure it.