It seems like in an infinite universe, there could be more than one planet that supports life. But we'll probably never come in contact with aliens because of distance and the limitations of our technology, which we're not improving because we haven't met any aliens yet. And so the cycle goes.
We aren't likely to be going anywhere outside our solar system since we use most of our technology and intelligence for destructive purposes (environmental destruction, war and weapons). We also have fairly short life spans and no capacity to enter a dormant state.
There's no real reason aliens couldn't come to us, with a few different - but plausible - characteristics. If they lived ten times as long, for example, or could enter a lengthy dormant state like sea monkeys, or invested as much in technology, research and space exploration as we do in war, crossing 13 light years (the
minimum distance to another habitable world) might not seem like such a big deal. Or they could send computerized research devices in place of living representatives.
That said, I am neutral on the subject of whether we will ever have definitive proof of aliens visiting. If it happened tomorrow I wouldn't be surprised. If it never happened in my life time I also wouldn't be surprised.