Why would Q waste the time? He could just post the question himself as anon and answer it as Q from another device.
The reason is information dissemination. To push the truth out into the public consciousness. So when the false reality breaks apart, enough anons will be available to salvage civilization. Meme. Spread truth. Ready yourself behind the glass that gets broken in case of emergency.
They play it in airports so they can count empty seats in gates and disembarking passengers walking by as 'viewers'