ChatGPT is so much more than just blog writing. So no, ChatGPT will never become useless at this point. It will only improve from here which is impressive.
As for punishment for blogs using AI-generated, I agree, this should be a punishment. The AI-generated content is not meant to be the sole "purpose" or point for writing. It is made to give "factual" data that has been compromised to cover a general idea of what you "input".
You are supposed to use that data and turn it into something of more unique value.
Doing so, you should be rewarded, I agree.