AI, and technology in general, isn’t making us dumber it’s just amplifying the already existing idiots that have always existed.

The problem is that in the past there have always been intelligent gatekeepers, intellectuals, artists, savvy business people, etc. that controlled the means of distribution and creation. First we saw the means of distribution become distributed and over the last 25 years we have seen idiots emerge from every corner of the internet. AI is helping break down the creation process in the same way.
So no we aren’t getting collectively dumber you are just seeing the idiots more frequent and in greater numbers than you used to.