UFO does not mean mean alien. I've seen some things that I think might be intelligent plasma or some kind of life form already on Earth we do not yet understand.
Another one of my unpopular theories is that perhaps sightings are associated with artificial intelligence from distant civilizations having launched a space probe to observe us. Or perhaps an AI built so well, it survived a civilization that has long since become dust right here on Earth.
Doesn't mean I do not believe the other "alien" ideas. Just pushing the thinking for what UFO means.
Or weirder still, maybe a civilization already exists close by that has advanced tech. They could either be under water, under ground, or perhaps on the moon.
Just do not ask me to accept anything Corey Goode claims. I am open, to a point. But treating it scientifically means applying some skepticism. But, not so much we ignore radar data and quality observations from pilots and astronauts.