Well I tend to think there is and has been even possible intelligent beings, b ut the main reasons I think there is life out there are 2 main factors.
The sheer numbers of galaxies and planets .
The Hubble telescope has been active for awhile, and its estimated that there are 125 billion galaxies in the observable universes. As for planets that's any bodys guess.
Next for me would be some examples on planet earth, namely extremophiles. For those of you who don't know what they are look it up. to me the water bear is a great example but there are many others.
As for truly intelligent life forms say with the intelligence of primitive humans or perhaps great apes or more intelligent creatures , its possible such species have came and gone as the universe is estimated at about 14.5 billion years old and earth is about 4.5 billion.
So such species could have come and gone in that time and we will never know about them.
They could be out there now even at our primitive level and we would never know.
What it takes for a planet like earth to form and be protected so that life can evolve is a amazing number of events to all line up over time.
It starts at the very beginning as dust lumps together and form a planet at just the right distance from a sun to hits from asteroids and meteors and comments carrying various organic materials, , the odd are not in life's favor at all but against it.
Yet Im sure the universe is teaming with basic like such as extremophiles and maybe more , spread over billions of light years apart.
We may indeed be the cream of the crop the most advanced species in the universe , which by the way is a sad thought .
Then again we may be very low on the scale of intelligence .
We will never know the answers and maybe that's a good thing I don't know.
For some reason I think we may have been visited in the past by a race of people who travel in space maybe in time like the adventures on the high seas, its just a feeling I get from reading history books and other material .
Again I will never know the answers to this in my life span but , I do wonder what others more advanced then us, if they do or did exist would think of us.
Its hard to think of the possible advances inn science and medicine and flight and space travel a species could develop given the time and conditions to do so.
Our own race has made huge strides in the last 140 years even with all the wars we had , and in the last 70 years these advances have been huge coming in leaps and bounds so to speak with amazing results .
I hope its humans from earth that end up being the top dog over time if we don't kill each other off first , I actually have a lot of faith in that .