So answer me this:
Your light has a neutral wire to complete the circuit.
Your smart switch requires a neutral wire to power the WiFi (low draw)
Older dryers (3-wire) did not have digital controls
NEC changed the code for new homes to be 4-wire so that there would be a neutral for the control circuit.
It is perfectly legal to run a new dryer (with controls) on a 3-wire circuit, i.e., uses ground to complete the control circuit.
What is the difference using the ground to complete the control circuit with a smart switch vs a dryer?