Plus Airbnb has reps all over the world helping hosts. If they had ten staff (photographers, sales, etc) in every city that has more than a million population that'd account for more than 5000 people alone.
I'm a superhost with only 5 listings one has over 100 reviews with 4.98 average rating. So far Airbnb has remotely adjudicated 2 guest disputes (on my 4 years of operations) that cost me $5k. Not trivial.
Dispute resolution is essentially marketing. When a host tells people they lost a dispute most people don't care because they're not going to be in that position. Most people can't afford to buy property to let on Airbnb. Even it they are in a position to buy and let a property, so long as Airbnb have more supply than demand then they're happy - they're getting every booking they can. Having another host in an area that already has hosts doesn't add much to their business. (If you were the only host in the area then you'd be much more likely to win disputes.)
When a guest tells people they lost then everyone can imagine being in that position, and might stop wanting to use Airbnb. That has a measurable impact on Airbnb's revenue.
The key thing to remember with any company that runs both sides of a marketplace is that they care about themselves more than either party in a dispute. I have no idea about the numbers, but if Airbnb side with hosts more than 10% of the time I'd be absolutely amazed. In popular areas it's probably less than 5%.
It’s analogous to the size of government and this trend of doing less with more.
Craigslist has 50 employees. I know there’s a ton of counter arguments to minimize my point but surely there’s a third way between 50 and 12,000.