For home automation I use Home Assistant, for several years now (~6-7). I had two goals when I began; no cloud and not critical path. Being a software engineer with a degree in electronic engineering it was no issue for me to build my own hardware with ESP32 or ESP8266 and create my own IoT devices.
The no-cloud thing has worked out pretty well, I still don't connect to anything in the cloud, and I block call-home functionality in my firewall such as that of the Philips Hue.
The non-critical path thing has been great too. I can control all of the lights with Hue switches or the physical switches, the sensors for motion can be disabled if we have certain guests that aren't tech-savvy enough (or frankly just used to) deal with motion sensing lights. The automations are all enhancements to rather than driving the core functionality of anything in the home, and so if/when it falls over, things go back to the "normal" level of convenient; you have to turn on lights yourself, or use various remotes for things, the heating becomes manual, etc.
Security is still hard in IoT, good security needs good hardware, and IoT is rarely that, and by good I mean decent memory, hardware accelerated encryption algorithms, hardware secure key storage etc. Coupled with the extremely poor programming practices of a lot of IoT devices, security is all but a joke.
If you're blocking your Philips Hue Bridge from connecting to the cloud, and you're a Home Assistant user, why not install the ZHA module and connect your lamps directly to HA instead of the Hue Bridge? I've been wanting to do this myself, but the prospect of losing access to both the native Hue app and the Hue Disco app is making it a hard sell in my household :)
I will certainly look into it as the Hue bridge accounts for a significant number of requests being blocked compared to my network's baseline.
An easy example is my pantry. It’s got a smart switch (Inovelli Zwave) hooked up for the light plus a door sensor on the door. Normally when you open the door the door sensor turns on the light by communicating with the smart switch and when you close the door the light goes off. But if everything is down the switch still acts like a regular light switch and you can turn the pantry lights off and on.
Other examples might be garage doors that open when they detect you pull in to the driveway. You want to make sure that you can still just press the garage door opener button so that you can get in like a normal person when presence detection fails.
Smart home functionality should enhance, not replace, at least until everything is 100% bullet proof and never fails or goes down (i.e. not in my lifetime)
The term "critical path" is when a whole system depends on that thing to function; it is in the critical path.
For example, if I couldn't use the lights at all when the home automation server is down, or your Mac won't run any programs when the phone-home server is down, those things are on the critical path, without them the system fails.
Only Tasmota or ESPHome flashable device for me from now on.
But the first step is to defang/block any device that tries to call home to its maker (which is why most of my non-ZigBee devices run Tasmota firmware).
None, as nobody is using them? IKEA zigbee remote is probably the one and only thing ever I saw on sale, and everyday use, and even they, saying this knowing an inside source, want to eventually switch to WiFi only.
And they are being outsold 100-to-1 by noname WiFi based gear, which unlike them, works on day 1 — a thing most people want, hence the sales success.
Proprietary systems by far established a reputation for themselves as "doesn't work with anything, even itself."
WiFi is not a candy either, and for most people it means an increasingly mounting pile of one per-device apps, but that's definitely better than not having the device working at all after every homekit/google home update.
From a purley anecdotal standpoint, you start with the wifi devices as they are low barrier to entry, (no hub required and normally comes with some sketchy 3rd part app); If you decide to go all in and buy more than a handful you naturally progress towards the zigbee/z-wave devices and ether a fully managed Proprietary "do it for me" system like SmartThings, or you go down the self managed route with HomeAssistant or OpenHAB.
No if you want secure, local control of your home automation you want Zigbee and Zwave devices not WiFi.
There is a TON of these devices on the market, and not just ikea like your other post seems to suggest
Hue works extremely well with a Hue hub. But it’s even better to get a non-proprietary hub to connect your devices.