I have a 2 part answer. First, what do I think are absolutely essential, at a minimum at even the cheapest airbnbs for 1 night - shampoo, conditioner, soap, toilet paper, 2 of each bath towel, hand towel and washcloth.
What do I provide? A whole lot more because I what guests to feel like they are staying in luxury. I provide high end shampoo, conditioner, body wash, body lotion, hair dryer, flat iron, curling iron, hair spray, mouthwash, sun screen, shaving cream, tissue, paper cups, q-tips, cotton balls, eye glass wipes, hand soap, spray deodorant, hair mouse, first aid kit and homemade sugar and salt scrubs. Plus bath mat, 6 bath towels, 4 beach towels, 8 hand towels and 12 wash cloths. If a couple is staying more than 3-4 days, I absolutely expect that everything will need to be washed and replaced for the remainer of their stay. I don't understand hosts that get annoyed if someone uses a lot of towels. It does not cost more to wash 6 towels vs 3 and I much rather share my house with someone who values cleanliness than is a slob.