The man tried to pass off a picture of a chandelier as a UFO. He claims he fought terrorists using astral projection. He's connected to the bullshit circus that is Skinwalker Ranch. He's not credible.
This is always the game with these people. Everyone's talking about Corbell's "jellyfish UAP" video - which is obviously just bird shit on the lens - and how there's a second video showing it leaping in and out of the water that definitely exists but of course that the public can never see. It's always allegations, claims, speculations, and rare circumstantial evidence that nine times out of ten turns out to be bunk. What has David Grusch actually revealed, other than a rehash of existing UFO folklore, and things he's been told by other people? It's all smoke and mirrors and people keep falling for it because of media hype, their inherent mistrust in government, and because they want to believe.
If there is something at the center of this - I promise you, I guarantee you the people talking about aliens and "NHIs" and interdimensional beings don't know anything about it.