The screens are restricted to showing protagonists doing, experiencing and talking, whereas books can ramble on forever about background.
Screen adaptations of background-rich books have three choices: simplify away the background, add new scenes engineered to convey background via protagonists, skip the background and let the viewer sink or swim on their own.
Readers who later watch an adaption are rarely happy with either option, but "simplify" is the worst. People new to the material rarely even notice "simplify", but fall into two very polarized camps for "engineer" and "skip". Just ask them about miniseries vs. Lynch Dune.
Personally, I love the feeling of only scratching the surface of a much deeper world, and I hate having everything spelled out in detail. As for The Expanse (TV only), I could have binged through ten seasons of life, death and intrigue in an industrialized collar system, could protomolecule ruined that, cancellation or not - guess I should read the first book for more of the good parts)