The question isn't so much whether "else" is used at all, but rather whether it's used as a conjunction. That's why the article author mentioned "or else": here "or" is the conjunction, so that proves "else" isn't fulfilling that role. In this example you gave:

> What else do you want to do?

"else" is acting like a noun rather than a conjunction (compare with "what activity do you want to do?).