It could, but this requires to store historical data about usage on devices. If you store that encrypted data in cloud, then getting it to your mobile phone is super slow. If you store it in cloud, you can get historical data even if your device is dead or has 256 BYTES of memory and 1 megabit of flash storage. We have such devices, very effective at managing local municipal heating network and controlling several thermal controllers each via rs232 or rs485. Fortunately we preemptively moved everything into VPN'ed mobile network, we need special approval to touch anything on that network and can't connect without them granting access, so after EU started moving with cybersecurity this year, we are covered.
> This also makes it simpler from a programming point of view - instead of having separate cloud sync & local control protocols, you just have one local protocol and you merely tunnel it through the (dumb) cloud if you can't connect directly.
Having only cloud protocol is even simpler, I've done all of the above (I do backend and our firmwares).
