Their might be some other limiting factor such that precludes technological development, but not intelligence. Their maybe some cultural or another hindrance we aren't taking into account.
The Idea that we and we alone or sole intelligence in the entire Universe seems to me to be an expression of utter hubris.
Maybe Einstein is right and there is no way to bend the rules and achieve faster than light travel, although I would not bet on it.
The Jews were God's chosen people, which did not limit the Creation to them or only allow them the spark of intelligence.
And one would arge that the Idea that we share the universe with countless other intelligent beings may simply be an expression of hope and a desire to not be alone in the universe. The only thing anyone can say without expressing wishful thinking or pessimism is that we just don't know if we are alone or not. Everything else is a guess.
Maybe Einstein is right and there is no way to bend the rules and achieve faster than light travel, although I would not bet on it.
The odds are likely that we'll never travel faster than light. See the "light cone" and causality. This isn't like claiming that no car will ever go over 60mph or no plane will ever break the sound barrier.
As a fan of science fiction, I'm not saying this because I like it. It's just what I see when I look at the evidence. Of course I also feel the same way about science fiction energy sources.
.....Their might be some other limiting factor ......
They came as insects and live among us as termites.