Is humanity alone in the Universe? What scientists think

We are almost certainly not alone according to laws of probability.

However .... The likelihood of ever meeting another set of intelligent creatures is highly unlikely, as the distances between the little islands of intelligence in the universe(s) are just too large to ever allow intelligent interchange of communication between them.

As an analogy, think of the various empires on earth a thousand or two years ago. The Aztecs never met Egyptians because they just couldn't span those "impossibly large" Earthly distances for that era.

But whereas humans managed to go faster and faster on Earth to Egyptians to meet Americans, the Speed of Light is a barrier to us meeting the inhabitants of the nearest island of intelligence to Earth even if it's only a couple of hundred light-years away.