Answer 1

its fading away for sure, RoR is more of a fullstack web framework, but the thing is its not as fast as the other framework.
non fullstack framework like expressjs just make it worse in its popularity, because how flexible they are progammers can work on their own personalized enviroment.

but just because RoR poplularity going down doesnt make it useless to learn ruby, who knows what kind of other technology will be develop in ruby in the future

Answer 2

// After 2018 it's demand is fading out but still popular, developer are switching in Jam stack, node now days , because everyone wants easy and shortcut. Id you are going to learn ruby on rails make sure your country/locality are hiring ruby developer, do research

Answer 3

Rails was more for the back end. I believe that the new JS based frameworks (e.g. Node.js) and Django/Python etc. have diminished the popularity of Ruby on Rails.