Maybe to encourage longer stays? The cleaning fee is paid once per stay, not once per night. I get why it is a separate charge, since they aren't cleaning the place daily (like a hotel), only at the end of your stay.

It is a dark pattern causing the advertised rate to be lower so the listing will get included in more filters etc.

[edit] I checked and they changed this in April of 2025, as of then the fee is rolled up in the advertised rate.

For us, we charge the same cleaning fee whether you stay for 1 night or 7 nights. So I don't know how we can incorporate that into the nightly fee without either over-charging or under-charging for cleaning. Having it listed separately keeps it consistent and clear to guests.

That was entirely on Airbnb for presenting it that way. Hosts would enter in their per-reservation cleaning cost so it could be integrated into the price paid by guests, but Airbnb stubbornly itemized it on the checkout page for years. I believe they finally did away with it (in favor of building into the nightly rate) about a year ago.

Because this way they can lie to you and offer low rates to pull you in until you go to check out.

In some locales, it is included