Yes - it has not been maintained since VTK 5.
But it was still usable.
I use VTK 7.1.1 with C++ Builder 11.3 and with the current version 12.2.
The current C++Builder version is CMake compatible again.
The current VTK can be build with it.
It shouldn’t be too difficult to re-include the code for the visual component/widget.