You are asking people that have been asking same question without getting the right answer themselves, the only way for everyone to know what will happen to bitcoin is when the remaining bitcoin has been fully mined. Anything you are seeing now are just mare speculation and nothing specific. Although many people believe that miners will be making their money from transaction charges, but we will only know about this after the entire bitcoin has been mined. But personally I believe that there will be a way for miners to get compensated when the entire bitcoin has been mined. So let's not get ourselves worked up over what will happen to bitcoin, because I know for sure that bitcoin will be here forever.
I believe say after miners done mine the last Bitcoin finish, the next thing be say the scarcity of Bitcoin go make the worth of bitcoin big. E.G: As we know say when product no dey for market again the price dey always hype (increase) well well. And with the way people dey adopt Bitcoin everyday if for the future miners done mine the last Bitcoin those wey hold their Bitcoin go get big profit if them won sell because that time the worth of bitcoin go too big pass today own. This limited supply way Bitcoin get na be the reason why many investors chose to hold onto their Bitcoin becuz them know say that time go reach and the value go increase.