Matter devices can be "dumb". They're intended to be able to work without Internet. Matter uses IP, and Thread provides IPV6, but that doesn't mean that either thing needs to be able to talk to the WAN.
Wifi devices can also be "dumb". For example: I have ESPHome devices that Just Work and that don't have any outside connectivity.
I don't advise anyone who asks me about smart home stuff. I'll tell them some about what I'm doing in my own home, and answer any questions they have accurately, but their eyes glaze over when they hear phrases like Zigbee or MQTT, and they've completely stopped listening by the time something like Home Assistant comes 'round.
I don't know that Matter and/or Thread will make anything better or more secure by default. The Matter 1.0 spec is only a year and a half old and it isn't clear at all how implementation is going to wind up being shaped in the real world.
But they can improve things and I hope that they will.
For devices I usually pick whatever standard has the device I want at a more reasonable price or is on sale. So far I've yet to run into a scenario where I wish I had chosen the other standard for a specific device.
I also have a ton of devices on WiFi via Esphome on both esp8266 & esp32. Fantastic project, years of them running completely trouble free.
Candeo are pretty reliable.
I think the ideal smart home device can connect to the internet to check for updates either when I manually want to update it or setup an auto update schedule. An account should NOT be required, which sadly lots of smart home hardware requires.
Thread is a transport protocol for Matter home automation protocol. Matter is complex because it tries to do everything in one protocol.
Zigbee and thread are different protocols and incompatible. You cannot mix them and that’s what most people are about.
What I've learned is that smart wall switches of all types are still too failure-prone for me. Now I'm converting back to standard wall switches with Z-wave relays wired in behind them. I don't like the extra lag they have, but I do like that standard wall switches last forever compared to smart wall switches.
If anyone knows how to reduce the lag, I'm all ears. The switch operates the relay which sends its signal to the hub, which then sends a signal back for the light to turn on. This process introduces a noticeable time delay between the switch closing and the light coming on.
My delay could be just that my hub is pretty old & needs to be updated.
Happily, that's not a goal and definitely not a requirement. Thread/Matter work great without internet access unless you use them via a platform which does (e.g. Alexa).
Beyond that, the protocol allows for logs to be uploaded to your ecosystem of choice, and allows for OTA installation of software updates.
Internet access is not a requirement for protocol, but neither is any other part of the modern “networked software” stack. Good luck with your internet-disabled SMTP server.
- Harder to get coverage. Both zigbee and zwave use mains powered devices (like light bulbs) as signal relays for other devices. If you're using both, you need to ensure proper coverage for both networks.
- No protocol native groups and scenes. At least zigbee allows you to set any number of bulbs to a certain scene using a single fast broadcast command. When using something like Home Assistant to unify both networks, recalling a scene will cause each individual bulb to be sent a separate command, which can be sloooow when you have many bulbs in one room.
Picking both is fine. Zigbee is significantly cheaper, but you have to make sure that the device is interoperable (Ecobee is a good example of a manufacturer to avoid - Zigbee interoperability is optional). If not, that's where Z-Wave steps in. Having an "off-brand" Zigbee adapter is a good bullshit force field. I use the Aoetec USB for Z-Wave and the Sonoff USB for Zigbee. Both are incredibly interoperability conscious, so I have no problem supporting them (I also have a lot of Zooz devices, who are equally awesome).
All the WiFi devices went to Goodwill.
But as a way to unburden your (usually one and only) Zigbee channel from certain types of chatty messaging, such as high-accuracy presence sending or complex lighting curve adjustments that can't be done ergonomically (or at all) via Zigbee, they are invaluable. Wifi (jailed in a VLAN, if you like) also provides a layer of failure protection should your Zigbee coordinator die unexpectedly.
One positive with Z-wave is that fallback is built into the protocol. So the switches can talk directly to the appropriate dimmer if the controller is down, for example.
Certain devices just aren't available in one or the other network, or are not cost effective.
In the end it's just one more USB stick.
I'm not super keen on Thread/Matter seeing how one of its goal seems to be allowing your devices access to the internet which is the exact opposite of what I want. I want my devices to be dumb, only able to talk to the hub, and then the hub can optionally run some code to connect outside the network if and when I decide.
The best part about my Z-Wave setup is every manufacturer can go out of business and I won't even notice. That's a stark difference to something WiFi based which almost always requires a cloud component. I understand why people start with WiFi devices, they don't need a hub, but having a local hub is the best way to do anything "smart home" by far. Personally I use Home Assistant but before that I used SmartThings and liked it well enough.