Yesterday while cooking I set off the smoke detector, no I did not burn anything. They go off when I cook over a high heat. And yesterday once they started going off they would not stop. I ended up having to disconnect them all (they are hard wired with an interconnect) and I replaced them this morning. Aaaaaaaand let me tell you, I had a sleepless night last night knowing there were no detectors installed.
https://www.southernliving.com/how-often-should-you-replace-smoke-detectors-8774122
Here in France rentals must have them, I believe. But I’ve never known anybody whose home caught fire. Maybe it has to do with building materials and regulations? In my région buildings are stone. My house had 90cm-thick granite walls. Radon is a bigger concern than fire.
Also in Italy, it’s rare for houses to catch fire.
But even if you live in a house made of concrete (Le Corbusier would be proud), things inside of the apartment can still catch fire.