🤷‍♂️ take it however you want to. It was only ever one strangers anonymous opinion on the Internet.

I can see an argument for Marx being the most influential politician philosopher of the the 19th century. But he is really only known for his political philosophy. Nietzsche is known for breakthroughs in multiple areas. And if I am being frank I have never heard of Hagel but I looked him up and would be interested in any recommendations you have on where to start with his works.

I would argue Plato and Aristotle are not contemporary. It could also be argued that Nietzsche is not either but he is definitely a philosopher of a different era than Plato and Aristotle and he definitely is one of the most influential of his era. Hell, I would argue he is the most influential of the 19th century but that’s more of an opinion.