They all offer more or less the same network services with different UIs.
OpenWRT is specifically designed to work as a lightweight system running on consumer-grade routers. If you want this, you’ll have to check the website’s Table Of Hardware to determine if your hardware is compatible.
OPNsense and pfSense are general-purpose FreeBSD-based operating systems that you can run on discrete computers or in VMs that act as network gateways. All three are free/gratis, but you have to make an account and go through the store page to download pfSense.