*on public roads
It’s completely legally for anyone of any age or mental capacity to buy a car and drive it on private property.
Guns are actually regulated more strictly than cars in most cases. Imagine your drivers license only being good in some states. Imagine if you got caught driving in a state where it wasn’t valid going to prison for 10 years. On top of that imagine if you had to be 21 rather than 16 to get a drivers license and the chief of police in your town could arbitrarily decide that you personally or your town as a whole couldn’t get licenses. Imagine if cars were banned based on their color or other aesthetic features. Imagine that only manual cars were legal for civilians but automatics were legal for law enforcement. Imagine if cars could only legally carry a certain amount of gas in the tank and cars with larger tanks would be illegal because they are deemed “high capacity”. Imagine if you had to get a background check every time you got new car. Imagine if you got one non-violent drug offense as a teen you could never legally own a car for your whole life.
Try to picture all that. Substitute car for firearms and that is the case currently.
I believe it shows a major lack of information on this subject to try(read as fail) to make the argument you are making.