FR-4 is less expensive than metal-core PCBs, but still, it is not preferred. The reason is that LEDs give off too much heat, so it’s necessary to have an excellent heat dissipation capability. FR-4 does not have that capability. Moreover, even if you want to use high heat-dissipating components in FR-4, you need to use heat sinks that take more space on the board. In contrast, aluminum can dissipate heat efficiently, and there is no need to use heat sinks because the base material is more than enough. The dielectric layer transfers the heat to the aluminum layer, and the PCB can efficiently dissipate a high volume of heat without any hassle. This is the reason components can work for a more extended period. Moreover, aluminum can withstand high temperatures; it does not bend or deteriorate. An LED PCB is more durable and long-lasting; therefore, it is preferred.