[masterofmisc]

I think another very important question to ask is "What version of C++ will you be using?" Is your companies codebase stuck on a pre 2011 version of C++ for some archaic reason? If so, I would be less inclined to touch that codebase.

Or is the codebase using a relatively modern standard (such as C++17 or C++20?)

Does the team track new versions of C++ upgrade every 3 years so your not left behind?

Remember if your not upgrading, it means you and your team is not able to take advantage of the latest C++ features. For example C++ 20 brought lots of goodies such as Modules, CoRoutines, Concepts and a new Ranges library.