@Lizzie I had a 100% response rate until the day airbnb stopped sending me text notifications, so I missed one inquiry (I responded in 25 hours instead of the 24) I notified airbnb right away about the text message glitch, which was not my fault, yet I still lost my 100% response rate.
I then started checking my airbnb account daily so I didn't miss anything. This is not easy from my end-I live where I have to use cell signal for internet, it is a metered connection and expensive, therefore I can't just leave it on all the time.
Text notifications started back up again two months after the glitch after numerous back and forth with Support. But there is still an unexplainable glitch in the system- guests who are in my time zone or an hour off, will message me at say 9PM, but the text notification doesn't come through until 3 in the morning. As I am not going to get up to answer at 3AM (and the guest will also be asleep) I do not, in fact, have 24 hours to respond, more like 12 hours from the time the guest sent the inquiry or booking request.
So hosts' response times are also dependent on the airbnb system working properly, which it doesn't.