Crib use is not universal, even in affluent countries. Culture influences where babies sleep, alongside whether families can afford a crib.

A 2010 study surveyed parents of 29,287 children from birth to three years old in 17 countries and regions. Reported bed-sharing ranged from 5.8% in New Zealand to 83.2% in Vietnam. The study used an internet survey and included toddlers, so it was not a worldwide census of infant crib use. Still, the results contradict the assumption that almost everyone uses cribs. [Cross-cultural sleep study](https://pubmed.ncbi.nlm.nih.gov/20138578/)

Other sleeping arrangements include:

- Floor futons or sleeping mats, particularly in Japan, either separate from or shared with parents. Research documents infant futons, including firm mattresses made for babies. These should not be treated as equivalent to adult futons or Western sofa-bed mattresses. [Japanese infant-bedding study](https://www.sciencedirect.com/science/article/pii/S0266613810002032)
- Sharing a parent’s bed, as the international survey illustrates. How common it is does not establish how safe it is.
- Bassinets, approved bedside sleepers, and portable cribs or play yards. These provide separate sleeping spaces without a conventional wooden crib. Bassinets have relatively limited allowances for a baby’s size and stage of development. [AAP recommendations](https://publications.aap.org/pediatrics/article/150/1/e2022057990/188304/Sleep-Related-Infant-Deaths-Updated-)

You’re right about one practical benefit of cribs: they keep a mobile baby within a small, controlled space while the parent sleeps. With an open floor bed, the baby can access the room, so furniture, cords, small objects, and gaps around the mattress all need attention. A raised sleeping surface mainly makes it easier to reach a young baby; height itself is not a requirement for safe infant sleep.

Preventing falls is only part of sleep safety. A floor mattress reduces fall height but can still pose suffocation or entrapment hazards. For babies under one year, current American Academy of Pediatrics guidance recommends a safety-approved crib, bassinet, portable crib, or play yard with its intended firm, flat mattress, a fitted sheet, and no soft objects or loose bedding. Babies should sleep on their backs and share their parents’ room on a separate sleeping surface, ideally for at least the first six months. An ordinary adult futon does not meet that recommendation simply because it sits on the floor. [AAP safe-sleep guidance](https://www.healthychildren.org/English/ages-stages/baby/sleep/Pages/A-Parents-Guide-to-Safe-Sleep.aspx)

Your friends’ arrangement has cultural precedents. That alone does not establish its claimed developmental advantages or its safety for an infant. After the bassinet, a crib or approved play yard is the straightforward choice. You can revisit a floor bed as your child gets older.