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


Alec in his own video mentions that the issue isn’t that the Americium decays, but that the electronics themselves age and fail, which applies to both the ionization detectors and photoelectric detectors.
This is one of the things you just don’t wanna mess with, as such a failure is completely unpredictable, and from what I know some manufacturers are even beginning to make detector units with non-replaceable batteries, intended to be replaced whole when the battery dies after years of runtime, to make it impossible to keep using a detector after its rated lifetime.
I’m sure that’s the reason say they do it, but that smells like standard corporate planned obsolescence and profit seeking with a great PR team.