Protocols
The short version: Zigbee is still the best overall workhorse for large device counts, Z-Wave is strong for locks/sensors in the right ecosystem, Thread is promising but still uneven, and Matter is a transport layer story more than a magic reliability fix.
Use Zigbee when
- You want lots of inexpensive sensors/plugs and a strong mesh.
- You can commit to a good hub/coordinator.
Use Z-Wave when
- You care about locks, security devices, and a more curated device ecosystem.
- You are okay with slightly higher device cost.
Use Thread when
- You already have strong Apple/Google/Nest border router support.
- You want modern low-power networking, but you accept ecosystem rough edges.
What Matter actually changes
Matter helps interoperability and onboarding, but it does not automatically fix weak Wi-Fi, poor border routers, or bad device firmware.