Let’s start a pool for this thread. How many posters will call the idea that life only exists on Earth “the height of arrogance.” I’ll take five.
No need for a pool.
Simple math would tell you that out of the trillions of stars in the Local Group alone that there is a high probability that there is some life somewhere out there.
It would honestly surprise me to find out in heaven that Earth really was the only planet with life on it. The Bible isn’t specific about that matter so we will never know for sure until we die or we come in contact with something.
It’s the opposite of the depths of humility.
Since "proof" is impossible, you can have a gazillion to one odds...
As they say in the casinos, "Good Luck!"