Not 100% sure why but my best guess would be: 1\. It takes time for the pick and place machines to load and unload reels of parts so raising that minimum parts count guarantees they are compensated a little bit for the time it takes when such low quantities are sold\. 2\. When loading/unloading reels\, there is likely some components lost in that process and they obviously need to pay for that lost product\. In large quantities\, they probably eat those costs themselves but when only selling 5pcs of $0\.001 resistor\, it doesn't make financial sense to cover those costs themselves\. The analogy I think of for this is when you load/unload 3D printer filament to change the color\, you loose/waist a little bit doing the extruder purge and cutting off the mangled end of unloaded filament\. Now take that tiny amount of filament and multiply the cost x100 since electronics aren't so cheap compared to plastic\.

@tayloramarotico Hello and thank you for the guesses : ) The minimum quantity has nothing related to the parts loss during assembly (basically we don't lose any piece because assembly is performed by machines). The needed Minimum Quantity is related to the assembly Pick & Place machine specifications.

If the minimum machine loading quantity is X and the customer only uses Y part in their board assembly run, what happens to the X-Y parts that are left unused in the machine at the end of theat assembly run? :)

No idea about JLCPCB, but I know the end-reels, offcuts and bins from many assembly houses end up in that marketplace cum warehouse in Shenzen where most of the traders on AliExpress get their stuff to sell.