... or you know CTRL-C/CTRL-V, cause there isn't really a good reason to prevent you pasting with a mouse.
I really don't get that
Docs overrides right click because there's things you'd naturally want to do in a word processor with right click (format, link, comment, etc). Because docs shows a custom menu on right click, the browser will not expose the default menu, and without the default menu, there's no JS copy/paste event.
Browser extensions have more access, and that's why a browser extension re-enables the functionality.
So it was a design choice: the Docs team decided that giving users all these other right click actions was more important than allowing the user to right click to copy/paste without an extension (since most people use the keyboard shortcuts anyway).
Most not-so-tech-savvy users I know, don't know keyboard shortcuts, find them hard to remember, clumsy and slow (at least until they learn how to really use them).
I think that googles decision was valid and the best compromise they could have made. I really don't see a way how they could achieve both, without compromising the user's privacy in a manner that doesn't require a specific browser or extension.
javascript:void(document.onmousedown=null);void(document.onclick=null);void(document.oncontextmenu=null)