just because a discussion is anonymous it doesnt mean its pointless

Discourse and dialogue on certain topics should be encouraged where the alternative might have been none at all. The information age has helped make more issues visible to society in this way. (If we go about it respectfully).

It allows anonymous conversation to take place with people from a multitude of backgrounds to expand our world view and potentially change our viewpoints of topics.

Arguing on the internet is a more accessible way to practice debate skills

It's fun.

why are you here then

It doesn't matter what medium an argument is taking place within, an argument can change peoples views for the better.

It's just as useful as arguing IRL. Some people might not take your arguments into consideration anyway.
Arguing is a great thing, but just with the right people.