For 20 years C++ was the recommended standard language, especially in the gaming industry. Mostly because it is fast and powerful, inheriting most programming language standards you can possibly think of.
Game and engine development have diverged for a while and the breach is only getting larger over time. Neither AAA nor indie studios build their own engines anymore, that job is now left to middleware developers. All that performance you're talking about needs to be done on the engine side of things, while game developers now instead focus on the higher level stuff - and that can be done with languages that aren't as close to the metal as C++.
It also says something about how complex the game industry has gotten now.