Aluminum extrusion requires that the PCB fit into the slots. Large PCBs are expensive to prototype and most of the space isn't necessary anymore. Also the encl

Aluminum extrusion requires that the PCB fit into the slots. Large PCBs are expensive to prototype and most of the space isn't necessary anymore. Also the enclosures are quite costly in comparison to plastic, and most aluminum enclosures don't provide any meaningful benefit other than EMI shielding (when grounded). They don't even act as a heatsink unless you go outside the generally expected methods. However at that point it's usually easier to throw on a heatsink and have ventilation holes. But yes I do love aluminum extruded chassis.