A 14-50 circuit is capable of outputting 12kW. Have you seen anything higher than 5.4kW?
The rating on the chargers built into our bikes is the charging limit we face, 3kW for Standard or 6kW for premium. The charger on the bike tells the ESVE (the cord that came with the bike, the one mounted in your garage, or the commercial charger you stop at) how much current it can take. From that point the amperage is limited by the hardware plugged into the bike. Whatever has the lowest rating will limit how fast we can charge.
I got an adapter so I can use the cord that came with the bike on a 50A RV outlet. My bike has a 6kW charger but will only charge at less than 4kW using this setup because the cord that came with the bike is only rated for 16A. It's the weakest link. Zero is coming out with a Charge Tank for the SR/f but it's not clear that it will do us any good for most applications. Most public J stations only can put out about 6kW.
I've plugged into a variety of different things and never seen a charging rate on the dash or app above 5.8kW