> beginners can use it without understanding too deeply...So there’s just going to be too many folks who will choose rails over more suitable languages.
It's not about "beginners" or "more suitable languages". You need an ability to build highly specialised software and you need general frameworks that will not be optimised for {specialised thing} but can do most of the things that you need for a certain task without having to hand write everything. Without the latter, all that happens is constant yak shaving and reinventions of the wheel. Rails (for example) is highly suitable for many things, getting clever points for not using it is great, but it's not very practical.
Bootcamps sell themselves based on employment placement, not cool technology or deep knowledge. In this regard RoR, Java, and even PHP are going to be bootcamp milch cows for years to come.
I’m not super convinced that’s a bad thing though. The software industry has always suffered a perennial shortage of engineers. What I predict will happen is that an ecosystem of tools will spring up around rails and there will be serious investment in improving performance rather than the framework being abandoned.
Remember how kubernetes changed infrastructure development to managing config files? It’s what I see happening to most areas of software development. The more experienced software engineers will then be responsible for optimizing/bug fixing/ scaling.