There are already settings to change some of the colors used.

For the terminal in particular there is an option to hide the menu bar, making it look as Foot or Alacritty do.

My patch to add Copy/Paste keycode support to the Cosmic Terminal was merged!

https://github.com/pop-os/cosmic-term/pull/481

The first time you accidentally type Control-C into a terminal and cancel an important process when you meant to copy some text it becomes a PITA.

Control+C is used to kill a process in the terminal and that shouldn’t be overwritten.

Agreed. The post didn’t suggest that.

Seems unnecessarily complex when Control+Shift+C works just fine.

For people already using programmable keyboards global copy/paste shortcuts are a nice perk.

I spend nearly all my day in a browser or a terminal and as I use a terminal and browser that already support this, the effect is 99% complete.