It's almost a joke: even opening up the flag menu has a three-second
Why is it a "joke"? It stops users and bots from spamming buttons and links where there is no need for such fast actions.
Such delays are on various site functionality, as with the many users and vast array of functionality some limits are required to stop flooding.
Instead of making a request to view the flag options every time
somebody opens the menu up, why aren't the menu options cached so that
the request isn't made twice, thus removing the need for a cooldown?
The flag options can change depending on the post state, and whether you have already flagged/voted or not.
So certain things have to be checked each time you click them.
Otherwise we'd have issues such as:
You cache the flags, including a "close" flag option, but the question becomes closed after you cache it. Then you provide the option to flag/vote to close an already closed question.
Also, caching takes resources, and it would probably use more resources than it does just having a 3 second delay.
I think it works ok as it is to be honest.
These things are not meant for speedy use, so such delays don't impede usage or the functionality in any way.