@Louisa I would suggest you familiarise yourself with Airbnb policy. They usually make payments 24 hours after a guest checks in. Yes they might make interest if a booking was made with sufficient advance payment but it is more a pre-caution i.e., if the guest is unable to keep the booking and cancels/ requires a refund, Airbnb have the money less any cancellation policy applicable in holding to immediately refund the guest. This might not be possible if the payment was released to the host in advance because the host may or may no longer have the money available to refund immediately; therefore it will be left to Airbnb to cover any payment refunds. From this point of view it makes sense that Airbnb hold any payments until such a time that the guest checks in. 24 hours gives the guest time to check into the accommodation and ensure it is as listed/ no other problems, it is reasonable that within this time the guest will know more or less if they are likely to stay the duration of their booking; it is also consider reasonable time for the guest to indicate if they do not wish to stay on in the accommodation hence the Airbnb's logic in holding funds.
Re receipt of the actual payments, so long as you have fully set up your Pay-out method, (please note that this is different from the Payment method) and there are no restrictions on minimum amount then the link below will give you an indication as to when to expect payments as it differs depending on your chosen payment method.
Hope this clarifies things a bit - https://www.airbnb.co.uk/help/article/425/when-do-i-get-paid
BW,Ama