Just want to add my feedback on this. In summary... If you go with the Simplified Pricing option, your host fees INCREASE from 3% to 15%.
INITIALLY this program was rolled out as an option for hosts to 'cover guest fees' aka take on the cost that Airbnb charges guests when they book. It was an easy no-brainer to say no. I definitely wasn't interested in my costs increasing.
Since then, Airbnb REBRANDED this to 'simplified' pricing. I didn't pay close enough attention and saw the airbnb example of... 'your earnings stay the same, but the guest sees a different rate per night'. however, it is up to you as the host to increase your prices in order to offset the increase in host fees.
There has to be some tax benefit to Airbnb by charging the hosts the full 15%. As a guest, sure it would be nice to have one less line item to look at during check out but at what cost to the host. Airbnb has intentionally made this pricing option opaque.