There are only 21 million total bitcoins that can be mined, what will happen if all bitcoin is already mined?
According to research if bitcoin reach its limit, it will be disappear but it doesn't happen already so don't worry. I think devs will solve the problem to extend.
Disappear to where? What research? simply state that this is your uninformed opinion. For starters, the blockchain will still be there so bitcoin is not going to disappear. Secondly, only worry of for miners as there will be no more block reward. But they will be sorted as they can still earn through transaction fees. But I think this will require the devs and bitcoin community to make changes on the blockchain. My 2 cents.