You're looking at this in a black and white way, overlooking all of the uses where it doesn't have to be perfect. If it saves humans even a few minutes, it's a good tool.
Absolutely. The user still needs good taste right now too - if it writes you a mission statement or something else you have still have to know whether its good or not.
That itself is an order of magnitude speed up. Even if AI never improves beyond this point (and it almost certainly will improve), it's already a game changer.