I find a lot of the grief with these protocols is driven by which wifi router is in use. When using the old Apple wifi routers I never had trouble with homekit, airdrop, handoff, airplay or any of the zeroconfig network stuff: as soon as I switched to other brands the issues would pop up (including ones that oddly seem to persist even after disconnecting from wifi - but then disappear when using a different user account on the same machine).
Because of this I feel Apple could do a hugely better job in all of their wireless protocols, as it stands the only truly stable networking appears to be between two iphones.
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.
I actually have the exact opposite experience. I have tried multiple different brands, all of which work JUST FINE with any other device, Android, internet connected devices, even my iPhones will work in every single room of my house.
Literally nothing I can do can make every HomePod on my network “just work”.
I would pay literally twice the amount of money for a HomePod with a fucking Ethernet port. Siri itself works amazingly well with it: when it can communicate.
The dream is to be able to wirelessly and effortlessly play music throughout my home, but I’m about to just give the fucking HomePods away and just wire speakers to every room in the house, even if it does cost more, it’ll actually fucking WORK.
Because of this I feel Apple could do a hugely better job in all of their wireless protocols, as it stands the only truly stable networking appears to be between two iphones.