I would say that for most frameworks/libraries. Keeping up with the Joneses is hard and Ember has taken particular care in both pioneering new ideas and bringing in new ideas from other domains and libraries. I'm just grateful that all the apps I have worked on since 1.13 have not been painless to upgrade, but have been totally worth it. Over the long term, stability, ergonomics and performance have been improving steadily and there has been a nice community around to help. That is about all I can ask for. Continuous improvement + nice people == recipe for software success over the long term.
For any indie developers, Ember can be extremely productive. In the past year, I have pushed out 3 moderately complex Ember apps in addition to having a full time job. I've reused some code for each application, have been able to depend on backwards compatibility for addons and always have received lots of help from other community members here: embercommunity.slack.com
This is mainly due to my ability to focus on shipping features rather than build processes. Also, depending on Ember Data, ember-cli-mirage, and the JSONAPI spec have allowed me quickly spec out how my schema will look, allowing me to move from the frontend to backend quite seamlessly. I've used React as well to develop widgets and such, but nothing has matched my ability to build, test, and ship features more than Ember.
We are all in this together and should focus on lifting all of us up. Positivity begets positivity.