I think most people believe that there is other lifeforms in the universe, but whether it have an intelligent matching our capabilities is another story.
One of the issues is that the Universe is big and old. So we don't really have any clue how long intelligent lifeforms exists, as they would most likely face a lot of the same issues as we have.
So looking at ourselves, we have already been very close to going extinct once, we could at pretty much any time be wiped out by something from space. We have managed to start an "extinction" of animals and plants on our own planet, pretty much in what you could call in a blink of an eye in cosmic time scale.
We have no effective defense against threats from space, we have no workable solution to the environmental issues we are facing. We have manage to create a global system, which is pretty much causing us to be stuck in a deadlock, which makes changes very difficult. We have fought wars from pretty much the dawn of man over resources, and despite facing a lot of issues, we continue to do so, which have just gotten worse in the scale of which we do this. And this is basically just in the last 1000 years. We still have no ways to actually leave and spread to other planets in an effective way, even if we were able to travel at the speed of light, the distance in space is so huge that it is very difficult to do so.
So putting it into perspective, looking at how we have manage to treat Earth in the last 1000 years and the Universe being roughly 14 billions years old, it would basically mean that even if modern humans manage to survive 50000 years, before going extinct, our existences in the Universe would be so short, that it could be considered a miracle if any other intelligent lifeforms should be living within a "reasonable" distance from us and be able to discover and even reach us in time, before we go extinct. The mere chance of them existing at the same time as us would be close to zero and most likely also possible to be considered a miracle.
In the end it completely depends on how easy it is for intelligent life to developer and survive and looking at ourselves, it seems to indicate that the chances for that is very low.
Definitely not, since we know that the Universe is expanding and things are moving further and further apart, which means that eventually we or anyone else won't even be able to see any stars in the night sky. And eventually the sun will consume Earth and the rest of the known solar system.
Agree this is what is important and only matters to lifeforms, the Universe does not seem to really favor life. As pretty much everything out there would instantly kill us and makes it extremely difficult to go anywhere. Despite humans ability to adapt to new environments, we have to develop extreme means of travel, but also being able to find suitable planets which can support us or terraform them to fit our needs.
Then you run into a new issue, which is gravity. For instance a person born on Mars, is most likely unable to travel to Earth and do well here due to the difference in gravity, as their bones might not be capable of that. So the amount of issues from spreading into space, even to the closest planet, is not something that is easily done and we have very limited data about how exactly this would turn out.
So at least in my opinion, if we want to survive, we have to learn to take care of Earth and each other first. Realize that humans are one species which fight is not among ourselves, but against the Universe