Chinese companies also make low-middle-end microcontrollers (gigadevice etc.), passive components, switches and connectors (clones of Japanese designs mostly) that are much lower cost and 'ok'. There's also PCB manufacturing and stuffing, tooling, injection molding (using Chinese or German machines), final assembly. For things like Bluetooth speakers, it's all local.. a wifi router might me be all local appart from the SOC.. iPhones yeah different story.