There is always a line to draw, why is this the point where you think it is important to draw a line?
It is totally reasonable to say "you may use AI tools in this class", or by comparison, "you must do research in this class, here are some ways you can do research, it is not cheating to use Google".
It is a very different thing to require the use of AI tools by someone who can competently write an essay on their own, or to require the use of Google by someone who happens to have a bunch of relevant sources bookmarked. That's moving from "can you do this" to "can you use this specific tool", and away from the actual point of the class.
Another example of this I can remember was requiring specific IDEs for some courses, which invariably led to a quarter of the class time being wasted explaining buttons in a now long-outdated version of Eclipse in excruciating detail, instead of any actual programming concepts or even Java-specific concepts.
But there are actual reasons to enforce the tool - in that case, so you can execute your code in a similar environment to your peers. It is specific, but that's the point of the restriction.