I've stayed in Airbnbs for the past two years. Can I please add "a decent working desk and chair?" But, for the rest, oh my god, yes!
Without the mattress and a decent working desk, I've had to invest in supplies of Perskindol - which isn't easily available in every country, let me tell you!
BTW, if you have cricks and muscle aches, I heartily endorse this product (I'm not paid to do this, I'm just a fan)