This is simply wrong, and missing the point, simultaneously.
Flight (like "intelligence") means more than one thing. Planes fly, birds fly, but they not only use a different mechanism, they can't even do the same kind of flying that the other does.
Sometimes, the difference doesn't matter. Sometimes it does. Same for "intelligence".
We don't actually know that much about how the brain works, and nobody discussing intelligence will decide tomorrow that humans aren't intelligent if the details of how the brain functions turn out to be slightly different from what we previously thought.
LLMs obviously display what everyone prior to 2022 would have called "intelligence," before the goalposts started rapidly shifting with the release of ChatGPT. They can carry conversations about arbitrary subjects, understanding what you're asking and formulating thoughtful answers at the level of a very smart and extremely well educated human. They're not identical to humans (e.g., they don't have fixed personalities), but they display what everyone commonly believes to be intelligence.
Flight (like "intelligence") means more than one thing. Planes fly, birds fly, but they not only use a different mechanism, they can't even do the same kind of flying that the other does.
Sometimes, the difference doesn't matter. Sometimes it does. Same for "intelligence".