We keep a cheap digital one in each of the bedrooms, but do try to make sure they are turned off so it doesn't wake up the next guests. I'm like @Lisa723 though, when traveling I either turn it face down or unplug it if I need the outlet to plug in a charger. The light keeps me awake at night.
I thought about it but my daughter said "forget it, everyone has smartphones today" I said maybe some older folks will not use smartphones and she said, "They don't use Airbnb either" . And she is right.
So, no we don't have an alarm clock, it's 2 batteries less to think about 🙂