I see you didn't actually read the link I pasted, especially not the section "Evaluating languages for projects". There's several possible ways you can compare (StackOverflow survey, JetBrains survey, GitHub PRs, StackOverflow trends, Google trends) but ultimately it comes down to what's a good fit for your project.
- Can developers be hired/trained to use it?
- Will they be happy using it?
- What will our development velocity be on this language? What will be the operational burden of keeping it running in production?
- Do we need to rely on third party code? Does that code already exist and what is its quality?
Only your team can answer these questions for your project in particular. It depends on your business problem, your local jobs market, your engineering budget.
I didn't make the claim that C++ is losing popularity, but I did mention some sources that do. These are marginal, not dramatic declines. Certainly not a terminal decline.
- Number of people searching Google - https://trends.google.com/trends/explore?date=2012-07-31%202...
- Number of questions asked on StackOverflow that month - https://insights.stackoverflow.com/trends?tags=java%2Cc%2B%2...
A far cry from the claim that it's "dominating and gaining", as you said.
FWIW, I've been a professional C++ programmer, and I like C++.
Below the list a graph showing the ratings over a 20 year period is provided. It shows C++ declining until about ~2017 but recently starting rising again.