They seem to be using a lot of chip surface to do some passive components (big featureless area) that are needed for the analog part. Going to 5nm will make the

They seem to be using a lot of chip surface to do some passive components (big featureless area) that are needed for the analog part. Going to 5nm will make the chip more expensive. The 5 micro-watts of power come from RF harvesting where they are constrained by law to only emit less than 2W. Bringing the emitter closer, they probably can afford a bigger power budget. It would be great if they could 10x the sampling frequency.