I have never had any clue as to the spark that started life. I would like to believe in abiogenesis but it does seem like a hell of a leap. Life from other planets seems even bigger.
They are both just as likely to be true to be honest. I advocate neither. Nor do i dismiss either. Although my thinking goes more the opposite of yours. Life from elsewhere or life from nothing.
Well, life from elsewhere makes more sense to me out of the two. But i do not believe either yet.