My BX750MI-GR has saved my precious data on two occasions. Earlier this year, my seven year old, well used waffle iron shorted, popping loudly and sparking quite brightly in the process, probably because of all the gunk that had accumulated inside its less cleanable interior over the years. That not only made my breaker trip, but also blew the 16 amp main fuse. The UPS kicked in immediately, making a klick and a beep, which felt amazing. That was my first time ever.
As for the second time, see this post.
I grew up in a place where home electricity wasn’t reliable and we got power outages several times a week. Portable UPS units like in the post were still pretty expensive back then and it was a luxury when we finally got one for our shared family computer. Our setup was basically power socket > AVR > UPS > PC.
My parents grew up in families who periodically lived with relatives who simply didn’t have electricity. Warmth came from a fireplace, cooking was done on a fire stove. Then, when they got back home, their boiler for the shower/bath still was heated with fire. I was so scared of that boiler, because the fire stove(?) was black. The boiler itself was white though.
Japan had a lot of power outages when I was living there. I don’t known for sure, but most of it surely was an automated response to earthquakes, while the minority was actual power lines snapping. This rarely happens there though, because most of their power lines - both urban and intercity ones - hang in the air instead of being buried in the ground to protect them from the earthquakes.