It seems that almost all of the Ruby on Rails job postings are for senior developers, usually with 5+ years experience, although I am aware of the caveat that one should not let that stop them from applying.
However, when looking at Ruby on Rails statistics such as year-over-year job listings or downloads, the framework seems fairly steady. I don't think it is in anyway declining.
By comparison, on my local slack/job sites , there are lots of junior JS listings, mostly React.
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