When filing a feedback request on the content blocker, I wanted to refer to the content blocker page, and the easiest way to do that was for me to quote some text on that page. ("The URL was blocked by a content blocker".) But that text isn't selectable, so I had to type it by hand, going back and forth between that page and the feedback form to make sure I was typing it correctly.
That page in question is a tab in my web browser, text on it should be selectable just like text is selectable on a regular web page, so I can copy and paste it.