Unless the context menu is not available, that is.

When is the context menu not be available? If the website is overriding the right click action, keep shift pressed while clicking to gain back control.

There are several pages on AWS that do not show it. For example, most CloudWatch pages.

I think it has to do with iframes.

You can shift+right click if a page (like the ones on AWS) block right clicks.

You can shift+right click normally too, even when a page doesn't block right click.

It's not about blocking or hijacking right-clicks. The menu option simply isn't there when the right-click happens in an iframe.