Qt isn't known for "using every C++ feature" at all. Quite to the contrary, as far as C++ goes, Qt is stuck in the old times BEFORE modern C++. And it really shows in the architecture, memory management and syntax. In fact, lots of Qt's non-gui stuff is precisely about features that were missing in standard C++ at the time and later found their way there, leaving Qt with its old non-standard stuff (including containers, smart pointers, etc) and its raw pointers everywhere.

Making a wrapper for Qt is not really any more complicated by Qt being written in (old-style) C++ than if it had been written in C. In fact, lots of languages do have Qt wrappers. As for Qt being object oriented… well, while that might indeed have been a problem for a language that is not… all your examples (rust, go, dart, D, ...) are, so that's hardly the problem there. Also, as far as the declarative and reactive goes: Qt does do that as well, and way better than any browser-lib-based webrendering engine (including mozilla's)

The real pain point with Qt is with its licensing at least since Qt was bought by Digia.