The author categorizes smart home tech into genuinely useful, cool-but-unnecessary, and a new third tier: more trouble than it's worth. His bathroom lighting exposed this trap. Philips Hue motion sensors worked in the kitchen but failed in the bathroom — infrared sensors can't detect a stationary person soaking in a tub, leaving the room dark.

He upgraded to Aqara FP300 and FP2 presence sensors, which use mmWave radar to detect micro-movements like breathing. The battery-powered FP300 proved less sensitive than the motion sensor it replaced, requiring exaggerated movement to trigger. The USB-powered FP2 initially passed the bath test but then hallucinated occupants, locking detection zones and ignoring real entries.

A week of resets, zone edits, and repositioning changed nothing. The author realized he had spent hours engineering a solution for a problem solved by a light switch. He returned the sensors, kept smart bulbs for dimming, and retained a Matter-Zigbee hub solely for temperature and humidity reporting.

The episode illustrates a growing friction in home automation: mmWave promise outpaces reliability, and marginal convenience gains rarely justify debugging sessions. Consumers should audit whether a "smart" upgrade actually reduces friction or just relocates it.