Looking into the code ... Wow ... This is not C++, it is C with classes ... https://github.com/defold/defold/blob/dev/engine/dlib/src/dm... Any reasons to use these wrappers instead of modern C++ capabilities?

There's a great post on that by the lead Defold dev: https://defold.com/2020/05/31/The-Defold-engine-code-style/

In the game industry, "C-like C++" is the norm. Games often don't use modern C++ features like exceptions, RTTI, multiple inheritance, etc. for very good reasons.