sbov parent
Also, most languages are not sinking ships. Certain uses of them are of course. But even languages this site hates, such as C, C++, C#, and Java have very long lives ahead of them for certain uses. Obviously C++ vs Rails... well, you're going to be out of a job. But if you were using C++ for the sorts of things you would have used Rails in 2009 you were already a decade or so behind the curve.
I doubt it. C++ has come a long way in the past decade and still has a lot of momentum.
As for rails? Admittedly I'm in an anti-ruby bubble... but the Ruby developers I do know definitely don't use Rails anymore. Ruby seems to have matured into basically just Chef/Vagrant in my bubble and any Rails apps are being deprecated in favor of the bubble-biased languages.
Rails developer here. It's still quite easy to get a Rails job; maybe not for Google, but easy. There's much less hype but also less competition over jobs (many young developers come with Python/Nodejs backgrounds nowadays, many senior Rubyists left for greener fields).