> Thanks to biology, not everyone can sing.

According to this, nearly everybody can, with training. https://www.theatlantic.com/health/archive/2015/02/everyone-...

I used to be a singer when I was younger, and I was good. But then I gave it up and without the continuous practice, my ability to carry a tune tunefully has severely diminished - my biology remains the same (well, add a few years), but my level of skill has dropped off, and hence so has my singing.

Tone isn't the only issue. Some people simply lack range.

Tonic and dynamic range can both be improved with an exercise regime, just like any other physical activity.