My smart home setup keeps suggesting I buy a new air purifier every time the PM2.5 reading spikes, and it made me realize how much of our tech already decides what we need before we do. Are predictive maintenance features in consumer devices actually saving us money, or are they just another way to push unnecessary upgrades? I've seen my phone nag me about battery health at 85%, and the replacement costs more than the phone's resale value. For me, the convenience of automation doesn't outweigh the constant pressure to spend, but I'm curious if others have had genuinely positive experiences with these features reducing their long-term costs.