The greater the number you are traveling with, and the longer you stay, the cheaper it will become compared to other accommodations.
You get to know someone else's home and surroundings, and get good advices about what to do.
You often can borrow things you need, from bicycles to games. Since you can wash your clothes, you can reduce your packing.
You are not locked out of mealtimes or guided tours. You take care of yourself and disposes over your own time
You will stay outside the normal tourist areas.
You get someone who is watering your flowers, taking care of your mail, and maybe mowing the grass and feeding the fish. Your home is not empty so the the risk of burglary decreases.