> Macs manage to make one-handed chords for copy and paste ergonomic
Cmd-C is not any more ergonomic than Ctrl-C. You are only speaking from position of habit. Pressing modifier with tucked in thumb is not great for it.
If someone is concerned about ergonomics, they should buy ergonomic keyboard. Standard layouts are crap.
Exactly. Either way the keys are too close together for comfortable, and quick, typing. The solution is to move your right hand back to the keyboard and to leave it there. Since selecting text is usually what you do right before you copy it, learn to select the text using keyboard commands.