I am inclined to think that there are other beings in the Universe. Some of them will even be sufficently like us for us to recognise them - and they us- as 'intelligent' (I use the word in its loosest sense).
However, I remain skeptical regarding claims about their presence and activities here on Earth. Unidentified Flying Objects remain just that - unidentified. We do not know what they are, and I for one am not sufficiently well-informed or incautious as to venture a dogmatic explanation for them.
In the matter of close encounters, I have this to say. For any race , no matter how advanced, interstellar travel will be expensive , difficult and dangerous. Therefore no aliens whose objectives we are capable of understanding would come all the way to this little world, only to appear before and communicate with obscure individuals on lonely roads. They would make contact with Governments and attempt to establish diplomatic and trade relations, openly and publicly, as we would were the positions to be reversed.
"They don't want us to know." Then they should stay out of sight or stay away. If all the sightings and contacts are errors on their part, then they are the biggest bunch of blithering incompetents outside the Civil Service.
"They want to learn about us, study us." We have a plethora of Universities, museums and libraries where they would be made most welcome. That's the place where a sensible ET would start, surely?
"We can't understand their motives" If they are so different, then they won't understand us either, and contact is a waste of everyones' time.
"They live unseen among us, learning about us." There's a word for people like that. Spies. When you spy on someone, you don't have their best interests at heart. Arrest the lot of them and have done with it!
"They're in secret contact with the governments of the world." The governments of the world cordially despise each other. Somebody would have let the cat out of the bag, if only to drop their current biggest rival in the proverbial! Governments are not known for their capacity to keep secrets, expecially from each other.
In sum, if and when ETs come to Earth, they will either remain unseen and unknown by EVERYONE, or they will announce themelves openly and publicly to EVERYONE. What they will NOT do is muck about about with people nobody will believe, or play silly games with jobbing politicians! That makes no sense at all, and the least we can ask is that the answer to such an important question should make sense.