I think it depends on where you are.

For example, KLM say that they no longer need passengers to reconfirm flights - yet when my partner flew with them to Accra last year he was told, on arrival, that he would absolutely have to reconfirm his flight back home.

I have not had to reconfirm flights in Europe or North America for at least ten years - with any schedule carrier. I believe that some seat-only charter arrangements still require reconfirmation for the homeward flight.