Carpet is cheaper. Very simple.

Materials are cheaper. Under the carpet is plywood. Cheap and you can use small pieces to fill without anyone seeing it. Parquet, even laminate, is much more expensive.

Installation is cheaper. Carpet takes no gerat skill to lay down, and it is fast. Tongue and groove hardwood floors need multiple layers below, skill to lay and float and a baseboard to match to cover the gap from the floating floor to the walls.