There are a few answers to the “Where are they?” question. One is that the parameters to the Drake equation mean life is so rare we actually are alone (as another commenter linked to). Another group of answers is that there is life, but something about the relationship between us means we don’t observe them. Maybe they’re hiding from us. Maybe they’re hiding from everyone.
I think the range of possible answers that people think of for this scenario is generally much too narrow. The power imbalances can be wildly greater than “they’re avoiding us”. We experience power imbalances this large every day. What’s the relationship between a Petri dish of bacteria and a person? Imagine a culture of penicillin reasoning how it came to be.
Maybe this universe is a total construction. Maybe it’s partially constructed, in the same way a farmer “makes” a farm from the Earth. If anything like that is the case, stochastic models are completely the wrong way to reason.
It would be like if I wove a basket. There’s now at least one basket made by Travis Jungroth. Surely there must be more? Out of the millions of baskets made across time, what’s the probability that only one was made by me? Even for a low probability of any individual basket, the numbers start getting decent there’s another out there.
But there’s not. I just… decided to make only one.