This is likely to protect landlords from tenants who would break shit during their stay and then claim it was broken before they showed up to get a refund.
Maybe. The main thing is that Airbnb keeps the payment for 24 hours after check-in, then it's released to the host. That means any complains within 24 hours will result in the payment being frozen. At the point it reaches the host's end, it's impossible to get the payment back without the host's approval.
Some things you simply don't notice at first sight (e.g tiny painting particles falling from the roof, cockroaches, a broken dishwasher..).
If Airbnb's review system were honest, this wouldn't be an issue, probably. In my experience, hotel reviews are magnitudes more reliable.