I think there are a few things to “prove” this won’t happen. This seems to be based on an assumption that we got more intelligent to reach this point, and that before tools and more high level stuff, we weren’t as intelligent. However, we were roughly as intelligent at that “beginning” of our species as we are now. You wouldn’t see much physical evidence of it, but our thoughts were allocated to other things like remember which plants to pick, and effective methods of hunting.

Also, you don’t just lose something through evolution if you don’t use it. I don’t know much about these cave fish, but they likely had a better rate of survival if they didn’t have eyes because the other fish were relying on them for a sense of location, but it was likely actually more harm than good.

Finally, we occupy our minds with other things. Just because I don’t have to calculate stats for some game that I like doesn’t mean that I don’t do it. People will find ways to continue to keep their brains challenged and engaged, or at least, the people that are doing that already.

In conclusion, no.