I know that even the US Air Force saw a UFO and took video. In my opinion, the time for jokes on this topic has already passed.
If we talk seriously. There are about 300 billion star systems in our Galaxy, 20-30% of these stars are yellow dwarfs (like our Sun). The age of these stars is up to 10 billion years (our Sun is 5 billion years old). Let's think about what heights a civilization 5 billion years older than ours can reach. And don’t say that we are alone in the Universe, our dinosaurs were alone, and aquatic life on our planet was alone in the Universe for half a billion years :)
I also forgot to say - there are hundreds of billions of Galaxies like ours (with hundreds of billions of stars) in the visible part of the Universe. We are alone because we don't see anyone in the radio range, they said...
I agree, it's inconceivable to think we are the only inhabited planet; there's life out there.
You raised a very interesting topic! Which few people can yet discuss seriously. All this is due to our backwardness and opinion "the most intelligent" at this point in the Universe. I think that we are still a very young civilization and, of course, we are under the microscope of more developed ones. I hope they are simply watching us, without interfering at all with the ecosystem of our planet.
Yeah, humans are not a very old bunch, several thousand years is a small span of time compared to the many millions the plant has been around...and then considering the universe...we are small and insignificant in comparison. I like to think we're being watched.