When you install a browser extension, your browser will notify you if it can read or modify page content before you enable it the first time. Using OPs tool is not unique in that it becomes vulnerable when paired with nefarious browser extensions, because all pages are. Https doesn't even solve that.

This is akin to some medicine saying that if paired with another specific medicine, you won't get desired results, and you are upset that it doesn't include a warning against combining the medicine with cyanide because you might die. The pairing with cyanide is irrelevant to the medicine and is just a side effect of cyanide.