My C and V key are literally the most worn keys on my keyboard. The letters are completely worn off, they’re by far my most used keys. That amount of use probably makes the contacts degrade and less reliable.
Windows 10 (I think?) introduced a “fancy clipboard” with history and multi paste and generally made it an “app”. In my experience the fancier it is the more failure points, since it’s no longer just a simple OS memory buffer, it has its own application logic.
Since it’s a global hotkey, the OS has to:
Handle the interrupt
Query the currently active window / application for a “copy” output of the currently highlighted context
Wait for a response
Place that response into a buffer of some sort
In a highly volatile asynchronous UI where the user can alt tab at any time, I imagine often what happens is that you just didn’t wait long enough for the data to actually copy. Pressing CTRL+C would be equivalent in reliability as waiting 2 seconds, but it’s more fun to press the button a bunch
I have unconfirmed theories.