I am pretty sure that fiat currency will never completely disappear or even if it is no longer used there will definitely be an upgraded version of it that will be introduced and will still be created by the government. So waiting for fiat money to disappear is just a waste of time and meaningless.
I invest in bitcoin and want to become financially free and have a better life. I don't think it's my responsibility to hold on to bitcoins and give them to my grandchildren while my parents, wife and children have to live a difficult life. There will be no freedom if you still live in poverty and don't have enough money to take care of yourself and your loved ones right now.