It's still dominant in gaming (though losing share to Unity/C#), system software, and high-performance computing (of which quantitative finance is a significant subset).

I would recommend not optimizing for number of job positions open, but for desirability of job positions. You can only have one job anyway. If you would be unhappy doing Python or Java it doesn't matter how many open positions there are, you're not going to want any of them. Concentrate on finding a niche that you can get really good at, and then figure out who's hiring for it.

Thank you for responding,

My thought process was, Larger the number of job postings, easier it would be to change companies (provided one has good enough coding skills).

Can you please elaborate on how to identify niche?

That's true, but you don't need hundreds of thousands of alternate companies. You're reasonably secure having 10+ that you could jump to. C++ is fine in that regards; where it becomes a problem is careers like aeronautical engineering or petroleum geology where you have a really specialized skillset that's used by only 2-3 dominant companies.

For finding a niche - basically you try out a bunch of different careers, problem domains, and skillsets, and specialize in one where a.) you enjoy the daily work involved b.) the people around you tell you you're pretty good at it and c.) you get paid reasonably well for it. It can take a fair bit of job-hopping and exploration to get there. Do this at the beginning of a career when it's expected of everyone.

It's still a thing for low level, systems software development, and I predict will be for quite some time. Even popular projects like Tensorflow has a C++ backend. Other newer programming languages in the space like Rust have shown promising adoption, but C++ has Lindy effect for it.

Thank you for responding, Can you suggest technology tracks, which current C++ Dev can migrate to without much effort. And still be relevant and in demand 5-6years down the line

I have seen a C++ quant position paying 500K a year. There are definitely opportunities.

Link please

It was a job spec I was emailed.