Slowly because it is being used by a huge amount of users, I think.
Today, Sam Altman is posted on X:
it’s super fun seeing people love images in chatgpt.
but our GPUs are melting.
we are going to temporarily introduce some rate limits while we work on making it more efficient. hopefully won’t be long!
chatgpt free tier will get 3 generations per day soon.
(also, we are refusing some generations that should be allowed; we are fixing these as fast we can.)