There is a circular dependency — the language strongly influences what libraries/engines can and will be written.
Bevy and Servo wouldn't exist without Rust. Unreal probably wouldn't succeed without C++.
Languages may also matter for other reasons than just their feature set. Node.js got traction specifically because it was JavaScript.
Even though Fortran had state-of-the-art numeric libraries, Python enabled numpy to have the sweet spot of usability with good enough speed.
The killer libraries need years of effort to build them. That won't happen if users don't want to use the language, or the language isn't good enough for the task.
For Swift to have killer libraries, users must first choose Swift to build them. Catch22.
Bevy and Servo wouldn't exist without Rust. Unreal probably wouldn't succeed without C++.
Languages may also matter for other reasons than just their feature set. Node.js got traction specifically because it was JavaScript.
Even though Fortran had state-of-the-art numeric libraries, Python enabled numpy to have the sweet spot of usability with good enough speed.
The killer libraries need years of effort to build them. That won't happen if users don't want to use the language, or the language isn't good enough for the task.
For Swift to have killer libraries, users must first choose Swift to build them. Catch22.