Homekit might limit you as far as hardware goes, but if you’re handy you can run a Home Assistant instance and connect Siri to just about anything: Z-wave senso

Homekit might limit you as far as hardware goes, but if you’re handy you can run a Home Assistant instance and connect Siri to just about anything: Z-wave sensors, Logitech Harmony Hub, non-HomeKit light bulbs, etc.