Flat-packed furniture is usually explained as a way to save the buyer money. The saving is real, and it comes from a specific place: the volume of empty space that would otherwise be transported.
Freight is priced by space
A lorry or a shipping container fills up on volume long before it reaches its weight limit for most household goods.
An assembled wardrobe is mostly air, so shipping it means paying to move that air across every leg of the journey.
Breaking the same item into flat panels can multiply the number of units in a container several times over, and the cost per item falls in proportion.
Warehousing follows the same arithmetic
Storage is charged by the space occupied, and flat boxes stack densely and predictably on pallets.
A distribution centre holding flat packs carries far more stock in the same building, which shortens delivery times without additional property.
Retail floors work the same way, allowing a shop to display one assembled example while holding sellable stock for the whole week in a fraction of the space an assembled range would occupy.
Damage rates fall
Assembled furniture is fragile in transit precisely at the joints, which are the parts under stress when a load shifts.
Flat panels are simple shapes that can be padded, boxed and stacked, and they survive handling that would loosen a glued frame.
Fewer damaged deliveries means fewer replacements and returns, which is a substantial cost in a category where a return journey is as expensive as the original delivery.
The format changes the design
Flat packing requires panels rather than curves, and fixings that a buyer can operate with a supplied tool.
That pushes design towards engineered boards, standardised thicknesses and hardware that can be inserted without clamps or drying time.
The characteristic look of the category is therefore a consequence of the shipping format, not a style choice that happens to accompany it.
Assembly labour moves to the buyer
Someone still has to build the item, and flat packing transfers that work from a paid worker to the customer.
The transfer only functions if the instructions are genuinely followable, which is why manufacturers invest heavily in wordless diagrams and pre-drilled parts.
Where assembly is too difficult, the saving reverses, because failed builds generate support calls, replacement parts and returns that cost more than factory assembly would have done. This is why the better manufacturers test their instructions on people who have never built the item before.