$3.5 is pretty expensive when you can get microcontroller chips for $0.5 or less in bulk. In general, "the industry" makes their own boards and modules, and pre

$3.5 is pretty expensive when you can get microcontroller chips for $0.5 or less in bulk. In general, "the industry" makes their own boards and modules, and prefers cutting off any excess cost and features in favor of getting cheaper microcontrollers to optimally integrate into a design. That is, unless said designs actually need wifi, in which case Espressif is actually a consideration, but otherwise STMicroelectronics or Nordic Semiconductors chips tend to be more cost-effective, and the latter has significant leniency on board design as it allows remapping nearly all pins.