Many teams I've been on and heard about consider the big "are we using exceptions?" question. This is code for "are we using modern C++?"
Once you aren't using exceptions, you are precluded from using the full power of the language and its libraries.
But many older codebases are exception-less, and it is perceived to be difficult to shoehorn exceptions into a codebase that doesn't expect them, or into a team that doesn't know how to use them, so the answer in such cases is often 'no.'
In my experience, modern C++ needs someone who is passionate about it on the team, who can't stand the sight of anything less, to push for it. It also needs to overcome the objections of those who want it to be more like the legacy code.
While I don't think that old-C++ codebases are going away very quickly, I do believe there are more of these passionate people in the world than there were five years ago. They face the same uphill battle they faced five years ago, but they are more likely to find kindred spirits.