> But you will not write a kernel in Swift as you will lose performance all over the place.
That used to be the argument against C and C++ in the 80 and 90's regarding 16 bit home computers.
Any serious developer would know that Assembly was the only proper way to write software that required real performance.
Yet a couple of decades later.
> But the 3D engines are written in C or C++.
It depends on what you are building. For an app it is not a big deal to be slower. But you will not write a kernel in Swift as you will lose performance all over the place.
Python/Javascript/Lua are used as scripting languages to create video games. But the 3D engines are written in C or C++.
Each tool has its use.