What is the point of trying to wirelessly link up a system that needs so much wiring in the first place, including electricity? This seems moronic, unless it’s for fun. And even then it’s pretty stupid.
Retrofitting new wires to every light fixture and switch in a house is unenviable. In some cases, impossible. Laminate floors can deprive you of subfloor access of a whole floor, running cables through existing stud walls is difficult at the best of times... Wirelessly linked smoke alarms are becoming extremely common now in the UK because outside a narrow envelope building regulations want linked alarms (linked eith…
Also becoming a baseline feature in detectors in the US, in my experience. New houses have been using wired interconnect for a long time now, but in the last couple years I've helped several older relatives upgrade their smoke detectors and even the cheap ones have wireless interconnect now.