Reasons why it's nice to have a 14-50 plug in your garage rather than a 6-50:

1: when an uncle stops by for a visit with his RV he can plug in.

2: the other outlets in your garage are likely on a shared circuit. The 14-50 is dedicated, so with a 14-50 to 5-15 adapter you can more safely plug in a high wattage appliance, like a space heater.

1 is why we ended up with 14-50 as the standard, too. Before there was much charging infrastructure, RV parks were a good place to get a semi-fast charge, and that meant a charger with a 14-50 plug.

2 is something I never thought of, I’ll have to keep that in mind.