"Wiki" says they have discovered nearly 2000 extra solar planets. So far it appears that NONE of them would even be remotely suitable for mankind. But they have also found that perhaps many more smaller, dimmer stars could also have earth like planets ... they just have not yet seen any.
1st of all, dont forget that it´s easier to detect BIG planets, meaning that most of what is being found so far are planets like our own gas giants, preferably much closer to the star.
2nd, lots of those "discovered" are not confirmed yet. Occasionally one of those "planets" are found to be something else, like an odd star or something, causing what made it look like there was a planet there.
And 3rd, even now there are a few planets that if they are what they look like, could definitely support life as we know it.
And 4th, that´s the thing, "life as we know it" may have zero relevance, life on earth might be the exception to the rule, we can´t know that until we have actually explored a bundle of planets elsewhere and either find something to compare with, or a distinct and constant absence of anything living.
So, what about UFOs? If they are spacecraft from someplace else, where did they come from? Right now we are kinda like the blind mouse trying to figure out an elephant by just touching one toe. But I suppose practically anything is possible or probable. Are seeing something or nothing?
Problem with UFO "sightings" is that over 99% are just crap, people seeing things that are not there, or seeing things as if they were something drastically different.
As an example, how many people understand that a mirage is not something you only see in the desert? That in fact, hot spots in cities (where asphalt or concrete heated by the sun earlier) can generate mirages as well. And in a city there´s plenty of lights and stuff to have people think they´re seeing some weird shit.
And then there was the guy that experimented with his "lightshow" hat. 1m diameter. And when he went out for walks with it at night, reports of UFOs gushed in, reporting anything up to objects hundreds of meters big.
Just from his 1m hat. Tells you something about how unreliable an average UFO report is.
I still think we may be the only act around right now.
Maybe, maybe not. We just don´t know until we can actually travel or sense across the stars.