This however is exactly the point, though not for the purpose of violating privacy.
Like bandwidth, providers have to provide for the the peaks.
This allows them to better plan their power systems instead of guessing where they need switches and more redundancy.
Agree that if a bad guy can nefariously check my usage and determine I am away by remotely reading the signal while parked in the street, this is concerning. As long as the data is collected in real-time but analysed after the fact, my concern / objection goes away.