Example B of earth being shittastic is the entirety of The Churn novella

The story for The Churn is entirely Earth based and provides a description of what the average life in a crowded, metropolitan city is like in the world of the Expanse. The city of Baltimore has given way to a multitude of crime bosses, and organized black markets. There are multiple bosses who each keep a "family" of personal guards that operate the smuggling of goods, illegal memory implants, weapons smuggling, cybernetic implants, and other illegal goods and services. The story takes place over the course of about two days.

They're kind of forced to by an outside context problem, to quote Banks.

In a very... Specific way.

Doesn't really matter as the show ends three books short. You probably want to read them though rather than try and pick up from book 7 after the show as lots of characters were changed a bit in the show and one is killed due to off screen drama who should survive.

Well my pants aren't fancy at all thank you very much :p.

The show is great, and so are the books. Mostly I would start by watching the show which is, for the first season at least, much more polished imho (the writers of the book were also show runners). After that, the show ends at book 6 (there are 9 total) but several character arcs are tweaked so I would recommend reading at least books 3 to 6 before 7.

Watch the show and then read the books. In my opinion the show is fantastic and incredibly enjoyable (except for ending the series in what is obviously the middle of a significant plot thread, which is annoying) but the books are even better and spoiled the show a tinsy bit for me.

Listen to the books, don't care about the show.

The population numbers sort of... even out later in the books.

So?