Using spell checks or Grammarly isn't the same thing as using AI. Not everyone is fluent in English and knows the language good enough to spell without making mistakes. That's where spell checkers help. But they don't create the content for you. They only correct the mistakes you made while writing. AIs generate everything for you, and they shouldn't be allowed. If it's against the rule to copy-paste from other people, it should also be against the rules to give an AI a prompt and just copy and paste what it generated on Bitcointalk.
I think you only have a partial picture of the issue. It's not just the spell checkers, the automatic translators have allowed a lot of people who have some idea of English and wrote poorly to now put what they think in their native language into the translator and paste the translated thing to post. In some cases it is noticeable but less and less.
On the other hand, AIs don't generate everything, as you say. They can be used in a similar way to spell checkers but to check all content. I had to send an email to about 20 people of some importance the other day. I wrote the email, and when I finished it I wasn't entirely convinced. I ran it through GPT Chat 4o saying who it was addressed to and to optimize it for me. The result was very good. He changed a few things for me, but only as many as I needed.
In the same way I think you could use AIs to, for example, if you want to create a thread, you write the OP and when you finish it you tell him to optimize it. Being honest of course, and leaving a note about it.
The thing is that the anti AI sentiment is so strong on this forum that it takes the edge off for me. I use it more and more, but not in the forum.