Secondly, although it has been done that way for a couple of centuries, that doesn’t prove anything.

Since no other way was tried, you can’t make assumptions about it being best, ie., you only have one test case to chose from.

If it is the best system then it is good not being always done that way but because there are reasons that make it better than any other system.

PS. This is not part of your question but the electoral system in the United States has changed and it was not always the way that it is now.

If no other way has been tried, how do we know this is the best method.

Also, recent, and past elections have resulted in the controversial debate that this is not a fair and good method. Simply STATING that it is does not make it so.