Like he was saying, it’s more than just power loss. It’s a way of “sanitizing” the power as it comes in. This is “usually” not a problem. But dirty power is arguably worse than power outages. If the voltages fluctuate or get low for whatever reason that puts a big strain on your power supplies.
This could happen because you run a vacuum on the same circuit and your house is old, guy down the street electrocutes himself or the power coming in from the electric company is ‘dirty’ because they have an issue with transformers or up stream somewhere. It can be imperceptible to you, but your tech notices.