There is no ANC that can block those, both because of volume and also because ANC only blocks constant noises like hums. It's terrible and sudden noises like alarms and honking.

Won't those cut right through the ANC just by volume alone? A domestic fire alarm is 85–120 dB, I don't think my airpods can mute that.

And of course there will always be fringe cases. What if I go to sleep with regular foam earplugs, what if I take a sleeping pill etc. Or what if the warning sound can't be engineered to fit a ANC friendly frequency, like somebody screaming, a car tire screech behind me and so on.