Our universe is huge. We dont even a number to describe the amount of planets out there.

If there is life on earth that come from a single cell organism, there will be millions of life forms that evolve.

Aliens is not fact more like a belief. I grew up with x-files so i want to believe.

If there are man made or alien made advanced crafts, governments and secret agencies in government will have vastly intelligence about them.

This is the interesting part and important part: if government approves that there are objects that uses technology and physics in different ways , this will challenge thousands of minds that will lead to disruption in the tech and physics.