basket
蔂 centers on a container used for carrying things: a basket, especially one used for manual labor or transport.
蔂 combines 艹 (grass) with 累, which likely contributes the sound and possibly the idea of piling or accumulating, suggesting a woven grass basket used for carrying loads.
The top grass radical 艹 suggests plant material, and the bottom 累 looks like piled threads or fibers. Picture a basket woven from grass and piled high with goods.
For ルイ, imagine a basket so full that it looks like a small ruin of piled goods: ruin -> ルイ, and the basket carries the load.