There’s a high chance that the election of Milei is a new epoch in global history and will lead to a rise of libertarian parties worldwide just as labor parties did. By all accounts Milei is shrewd and has a good chance to succeed.
Argentina has a very particular situation and Milei policies hasn't been that much different to what right wingers in other country would do in his case.
Is Chris Watson really remembered for much other than being the first world leader from a labor party? He depended on Alfred Deakin for confidence and supply and his government didn't end up being very different from what any other protectionist government would have done at that time. It was still a milestone in the history of the labor movement, though.