Finally, I have finished Judea Pearl's latest work "The Book of Why"! Having read it, I have come to appreciate how much work had to go on in order to formalize the very intuitions that we have for causal reasoning into essentially a modelling language.
"The Book of Why" is geared towards the layman reader. Thus, unlike a textbook, it does not contain "simplest complex examples" that a reader can walk through and do calculations by hand (or through simulation). Thankfully, there is a lecture series by Jonas Peters, organized by the Broad Institute and held at MIT, that are available freely online.
From just viewing the first of the four lectures, I am thoroughly enjoying Jonas' explanations of the core ideas in causal modelling. Indeed, Jonas is a very talented lecturer! He builds up the ideas from simple examples, finally culminating in a "simple complex example" that we can simulate on a computer. Having just freshly read "The Book of Why" also helps immensely; it's also clear to me that people in the world of causal modelling are very much familiar with the same talking points. For those interested in learning more about causal modelling, I highly recommend both the book and the lecture series!