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.

Same here. I would say total power outages are a bit more rare than every three years. But we had some failure last year and two years before that a neighbor dug through some cables and most of the street went dark. Sometimes I contribute and plug in some (old) electrical device that isn't okay anymore. This year I got some water into the extension cord while cleaning outside... And since we have ground fault protection for the house, I had to reboot everything. The server and the 4 harddisks in it are perfectly fine. And have been for like a decade. I don't think I need to pay for an UPS and the additional power it needs.