This is a question between the scientists and the conspiracy theorists.
Forget all the sci-fi films you have watched or the novels you have read. Have you encountered an Alien. I have not encountered one but I believe there should be.
I believe it is not everything the government sees they let the general public knows about. They have top secrets they keep. Aliens π½ are one of them.
There have been cases of UFO spottings, many are quickly debunked by the Governments and termed something else.
I believe it won't take a long time before we see a real Alien that the government can't deny.
The existence of aliens hasn't been confirmed by anyone but conspiracy theorists, so I wouldn't say that they are real. I believe that if there are aliens, we haven't discovered their existence yet, and if we have, everyone just assumed the "discoverer" was crazy or misled.
There are people who swear they have had contact with aliens, but there are also people who swear they have talked to God, to their dead family members, to ghosts, and that they have seen witchcraft being performed and all other sorts of supernatural things that nobody can verify and are probably not real.
So, whether aliens are real or not, we can't know, but I prefer to assume they aren't and I just live my earthy life in peace.