If I want to use an Apple TV as a HomeKit Hub to help control wireless devices (like smart locks), does the Apple TV need to be physically close to those wireless devices or does it use your existing Wi-Fi network to connect?

(I’m going to using the Schlage Encode Plus)

@tvaziri distance does not matter, but connecting the Apple TV with a cable sure does. That helps to eliminate connection problems with the hub itself. Homekit has many other issues, it's worth it to eliminate that one.
@pl @tvaziri Generally this is good advice, I had an issue (and so did others) trying to use an Apple TV as a HomeKit hub when connected via Ethernet. Going to WiFi solved it, but YMMV. https://www.reddit.com/r/HomeKit/comments/1272fm6/apple_tv_4k_2022_ethernet_cable_and_homekit/