Umm, I really don't know what the future holds for bitcoin, and highly doubt that it will topple all banks or replace FIAT currencies altogether. But I do think it's probable that it finds its niche or application where it may surpass our wildest dreams, still!
Yes maybe bitcoin cant replace that but we are hoping that there would be a good improvement like it will be widely accepted in many countries and can use to purchase items as regular currency. if that happens it will be a good future ahead of us.