I use Home Assistant and a mixture of Z-wave and wifi devices. The way I choose wifi devices is by finding which ones can have Tasmota firmware flashed to them.
For example, in Australia, many hardware stores sell “Grid Connect” devices. This is a cloud solution for the likes of Arlec. However, most of these devices can be flashed with Tasmota. This removes the cloud and keeps everything in house using MQTT. Security is WPA2 and TLS. I run my IOT devices on a separate VLAN and use 2.4Ghz network as it seems to have more coverage and is more reliable.
Here is a list of >2000 devices which can take the Tasmota firmware:
For example, in Australia, many hardware stores sell “Grid Connect” devices. This is a cloud solution for the likes of Arlec. However, most of these devices can be flashed with Tasmota. This removes the cloud and keeps everything in house using MQTT. Security is WPA2 and TLS. I run my IOT devices on a separate VLAN and use 2.4Ghz network as it seems to have more coverage and is more reliable.
Here is a list of >2000 devices which can take the Tasmota firmware:
https://templates.blakadder.com/