Let’ say that the probability of an intelligent life on any planet is weak. But as there are milliards of planets, the probability that intelligent life exists in the universe is rather high.
Now, given the infinity of time and universe, the probability that we meet them is rather week.
To make a comparison: the probability that any one wins at a national lottery is rather weak, but as millions of people play, there are winners.
Now, to meet them would mean that two neighbors win at the national lottery the same day.
And, if you add that the neighbors live in oasis, in a desert, hundred of kilometers apart, without any efficient way to travel from an oasis to another one.