So this is a random world idea that popped into my head a couple days ago and has been nagging at me ever since. I'm looking to get some outside perspective, ideas, suggestions and general brainstorming.

This setting is intended for D&D 5e

The basic idea is a world not unlike our own with advanced technology hits an apocalyptic event. Their civilization collapses leaving behind nothing but ruined cities and the automated robot construction plants that keep churning out animalistic robots that stalk the wild lands. In the aftermath, humanity limps on, and new races appear to share the world (Currently thinking Dwarves, Warforged, Tinker Gnomes, Sayre, and maybe Rougaru. Still waffling on what to allow). Along with new races comes, of course, magic.

The decades roll past and civilization manages to rebuild to the point of old west technology. Steam engines, revolvers and maybe the very first primitive automobiles. However, another big change that occurs is the return of dinosaurs, which take the place of most domesticated work animals. Rather than horses, people ride raptors, rather than cows people herd triceratops, etc.

So, something like Red Dead Redemption crossed with Horizon Zero Dawn with a splash of Jurassic Park for flavor.

That's about as far as I've gotten so far. Just some loose ideas I've cobbled together and am attempting to hammer into a usable setting.

Thoughts?