Nice project you got, and as @nickrout said, it’s envious that u can wire you house.
In my opinion wiring your entire house from a central location for all sensors isn’t the best. Except you want to use voltage balancing in signal transmission coupled with STP cabling.
If you don’t it will only input noise into your system, especially if u have stuffs like washing machine, dryers, HVAC or other high inductive loads on in the house. In short any strong EMC generator.
The desire to avoid WiFi is legit as I will do same, but instead of trying to have all the twisted pair cables run to the center, I would follow the advice of @nickrout and use the ESP chips over Twisted pair Ethernet cables using MQTT. Besides, the idea of using USB is a lot of work. There is a possibility the allocated name might change when the Pi reboots, or the connection being flaky over time. USB is not as rugged as Ethernet that is properly crimped or punched down.
What you can do is run a single network cable to each location, and connect an ESP chip to that cable to manage that location. Like each location having its own ESP chip over the network. Ethernet will help you manage the long runs, and this will ensure your signals are legit and less prone to interference.
This to me is not only better but more reliable and robust. I get Its not the cheapest, but could be depending on how u allocate the chip to the locations. You don’t want a system that just works, you need a system that is robust and future prove. With the Ethernet cable, u can easily expand over time as more things come up by simply changing the chip that manages that location.
You said it might be hard software wise, but there are tons of code out there based on ESP MQTT that u can modify for your use case. You got time, so why the rush? Better you build something robust now and safe you a headache in the future, than just rush it and u potentially regret it later on.