I think it's strange that you don't believe in it, but use a lot of thoughts around it that you use to explain that it's a lie.
Furthermore, this kind of information has been leaked for many years, by people who have worked in those places.
And they have told in detail what those vehicles look like and what they do. And even what extraterrestrials look like who are held captive.
Belief can also be fueled by emotional needs, such as a desire for meaning, security, hope, or control. It can be comforting to believe in something or not.
And it may also have to do with social acceptance.
Sometimes it is better to first see whether you are credible before you distrust something or someone.
I think those vehicles really fly around, there are so many reports of pilots and astronauts, you can't ignore that.
If you see the progress our own technology is making, then it is not at all surprising that there are civilizations that are much further than us.
The crazy thing is that we humans practically never doubt our head, while that is the biggest lying machine that exists.

Just look at how big there head is the are much more clever.
Furder more, they don,t doubt our existence.....