I setup my pi without keyboard and monitor (ssh only), and used this guide to set it up itself: https://www.losant.com/blog/getting-started-with-the-raspber...
Here's the list of my hardware: https://www.canakit.com/raspberry-pi-zero-wireless.html https://www.canakit.com/raspberry-pi-camera-v2-8mp.html
One is bolted to a utility pole outdoors, 200+ft away from the nearest WiFi access point through several walls. It's not a high link speed, but it works with nothing but that little triangle PCB trace cutout for the antenna.
For example if you need a big PCB, cheaper to make a big 2- or 4-layer PCB and put a module on it than to make your entire PCB 10 layers so you can break out a tiny BGA.
I've seen several commercial products that are just Pi-in-a-box, for small runs it's fine.