A marketplace takes a cut of every charter you run, forever, and keeps the customer. A flat plan does not. Put your own numbers in and see the gap for a year.
Enter the rate your platform actually charges. Marketplaces commonly bill the operator and add a separate renter fee on top, so the true figure is often higher than the headline rate. Charter OS charges no commission at any volume, and your customers stay yours.
The commission is the visible cost. The real one is that the guest belongs to the platform: their email, their booking history, their next trip. Charter OS runs under your name on your domain, so the repeat booking comes back to you instead of being sold to you a second time.