You can't really slap an AT motherboard in an LED light bulb and call it a day. Fabs produce all manner of chips, not just GPUs and CPUs.
Over the last 40 years all manner of circuits composed of discrete components have been replaced with chips. Voltage regulation is a chip, battery protection is a chip, rectification is a chip.
Over the last 40 years all manner of circuits composed of discrete components have been replaced with chips. Voltage regulation is a chip, battery protection is a chip, rectification is a chip.