It’s a game of numbers. There may be 10^n opportunities for life potentially forming, with the average likelihood for life actually forming being 10^-m for each. The question is, is n (much) larger than m, or vice versa? We really have no idea, in particular with regard to m. It doesn’t help if n is 100 when m may be 1000. And the human brain is really bad at estimating such likelihoods.