As a programming practice in service of the principle of least privilege, that would make complete sense.
The issue is with Apple's UX. Apple insists on asking permission for every little capability an app wants. So I would have to say "yes, allow this app to take screenshots" and "yes, allow this app to read the clipboard".
I wouldn't be surprised if, in the near future, Apple forced people to click "yes, allow this app to read the clipboard from app X" and then separately "yes, allow this app to read the clipboard for app Y" and so on for every single other app on my machine.
Apple does not allow you to say, "yes, I trust this #$@-ing app, please allow it to do whatever it needs."
accessibility.screenshot accessibility.paste
and whatever else there is. that completely removes the issues for apps like this.