No, it’s not reasonable to believe we’re alone. It’s far, far more probable that we’re not alone.
Absolutely nothing in the observable universe happens just once, and that fact alone should lead folks to believe that life is just as abundant as everything else. Inductive reasoning brought me to that conclusion a long time ago.
One thing happened once, life on a planet. You ignore the available evidence and then assert that nothing happens once. Easy to have the answer you want when you just make things up. Also, the comment says at this time. They say the universe is billions of years old and humanity is 50 thousand years old at the high estimate. The idea that in this block of time out of billions of years everyone started )or living )at exactly this time is probably statistically very low. I think it would be nice to meet other civilizations and they’re all worshipers of Jesus and only on Earth is it still debated 😂