We've never had an interaction a host with airbnb where anything meaningful has been done on their part when difficulties arise with guests.
And, before anyone asks what sort of hosts we are, we've been hosting for years now with superhost status and average 4.9 star reviews.
Two egregious circumstances come to mind that point out what I'm talking about.
1) Recently had a guest who, despite clear statements made on our page, started smoking weed right away upon arrival. Let me be clear, he was SMOKING OUT. The neighbors probably thought we were morons. Mr. 805, as he called himself, was an asshat all the way. He picked up on the fact we didn't like what he was doing, although we said nothing directly to confront him, and made a total mess of the place and left it that way. He defecated in the toilet repeatedly without flushing, and left it that way which resulted in a plumber being called to take care of it. He urinated on the floor at the entrance of our place. He left trash everywhere.
2) A guest just cancelled at the last moment claiming medical emergency and was granted a 100% refund, without any discussion with us. Not being a major operation such as an airline or large accommodation, we can't easily absorb such things and can't get replacement bookings even by lowering rates at a moments notice. None of this matters in the least in airbnb's eyes with the result being they just take a dump on hosts, even hosts who are doing a great job and actually host as they indicate on their page's description.
There have been numerous other situations where we've had issues with guests for which the response has been the same, nothing. Airbnb is there for one thing, and one thing only, to collect fees. Customer service to hosts, from whom they make their money, is non-existent.