More affordable, no. In my recent travels to NYC and SF, I was always able to get a hotel room via HotelTonight or Hotwire cheaper than an AirBnB unit. I know its not always an apples-to-apples comparison but even for just a private room (not an entire home), an AirBnB in SF is $100+/night.[1]
All that to say, I think you're wrong.
[0] https://medium.com/stay-woke/i-read-about-this-phenomenon-of...
[1] I randomly checked Dec 18-20 in SF. Hotwire has a 4-star room for $91/night. Most AirBnB private rooms are the same or higher.
For your suggested dates of Dec 18-20 I found literally dozens of AirBnBs for <$80/night. [0] All I can conclude is that you're straight up lying. It's trivially easier to find AirBnBs which are cheaper than hotels.
[0] https://www.airbnb.com/s/San-Francisco--CA--United-States?gu...
Take that for what its worth. If I'm objectively wrong or a liar to you, cool.
The average hotel room in SF costs hundreds of dollars a night. [0] So the average hotel is much more expensive than the average AirBnB.
Likewise, I showed countless examples of AirBnBs which have a lower price than the cheapest hotel you could find.
If both the average and the minimum for AirBnB is much lower than for hotels, we can safely conclude that AirBnB is substantially cheaper.
As a frequent traveler, I know that to be a fact. I would love if hotels were cheaper than AirBnB (I prefer them), but it's objectively not true.
[0] http://www.bizjournals.com/sanfrancisco/morning_call/2015/07...
source: traveling for 1.5 years using airbnb, hotels, hostels.
Private room airbnb is probably not the best deal.