There's a pretty big difference here though. In the case of Unity, most of the very hot code is C++. With a custom Rust engine, most of it is Rust.
Secondly, there is the ongoing rewrite from C++ into HPC#.
Third, I still remember the days when Pascal, Basic and C compilers were deemed worthless for professional game engines, followed by similar remarks to C++, back when Abrash books were still hot of the press.
Finally, languages don't dictate how fun games are and how much they sell.