Aside from cleaning and restocking (which is part and parcel of hosting) , I'd say the biggest pain is vetting guests. It's work.
And then, some of which seem to take offence to being asked questions like "you don't seem to have a profile or history on Airbnb. We want our guests to truly enjoy their stay, so perhaps you could tell me a bit about yourself and the nature of your visit". It's easy if their responses are blatantly obviously "off" in some way.. You know the drill.
But when they get offended or become angry, I try to cut them off politely, but sometimes they drag it out. It gets irritating. You're not going to get the booking, so just quit while you're ahead 🤨
A close 2nd is messy guests. That's also work, but fortunately they're in the minority.