If you want to say AI have reached intellectual Excellence because we have a few that have peaked in specific topics I would argue that those are so custom and bespoke that they are primarily a reflection on their human creators. Things like Champions and specific games or solutions to specific hard algorithms are not generally repurposable, and all of the general AI we have are a little bit dumb and when they work well they produce results that are generally mid. On occasionally we can get a few things we can sneak by and say they're better but that's hardly a commodity that's people sifting through large piles of mid for gems.

There are a lot of ways if it did reach intellectual excellence that we could argue that it would make Humanity more mediocre, I'm not sure I buy such arguments but there are lots of them and I can't say they're all categorically wrong.