It goes without saying that a 5-20 outlet should be on the correct wiring/breaker, just like a 14-50 outlet should have the correct wiring/breaker. All outlets should have the correct wiring/breaker.Only if the wiring / breaker allows. A NEMA 14-50 with UMC is still the most cost effective method of home charging.
Saying 120V is limited to 12 amps is not true since 16 amps is supported on 120V with a 5-20 outlet and adapter.