As someone who has moved from using Ember daily for 2+ years to now using React/Redux, I miss Ember on a daily basis. React suffers from lack of standardization like no other. I hate starting a new project or working on an existing project and having to think about where to put things. Ember grew from developers who existed in the Rails space and understood that convention over configuration is the way to go. React devs likely came from Express land where everything is composed of tiny modules that you'll spend days carefully putting them all together.

The React world is the wild west. Libraries come and go so quickly that you're better off building it yourself if you see your app as long living. Ember, on the other hand, does a great job of keeping everything in check. Because the community is so small, things just work because there's less things to maintain.

Admittedly, when I first got into Ember, it was pre 1.0 days. Even prior to v2.0, Ember struggled to keep things working as intended. Now that the framework has matured, most pain points have gone away. The way they do their versioning is the smartest in the industry. React has been around for years and still the community seems fragmented.

What it boils down to is:

Is your app fairly small and intended to only last about a year? Use React

Is your app core to your business used by many and intended to last for the foreseeable future? Use Ember