Specifically with Homekit, a wired Apple TV and good quality home networking equipment with wired access points makes a world of difference. I use Aruba Instant On, but I have had good experiences with Orbi at higher prices and Linksys Velop at the lower end from Costco. Also, if you have a lot of Homekit stuff, it is best to use devices that have their own Zwave or Zigbee or whatever hubs that are then connected via ethernet into your network, to cut down on how much chit chat is flying around on WiFi, especially from cheaper quality homekit devices.

I am overall unimpressed with the consistency of wireless technologies, especially since Apple no longer makes the equipment that provides the backbone (the router/access points). You usually have no idea what quality radios and programming various wireless devices are equipped with, so it is just a crapshoot when dealing with it.