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.
i think bitcoin will start disappear before that, it will end like a fashion sidenote among cryptocurrencies/token that will come in the future that will basically be like investments funds bank accounts and be strictly backed by existing assets and organisations and have a strict audit unlike bitcoin that just is an empty anonymous IT system. additionally there will be cybercrime organisations and syndicates that might hiddenly try to do 51% attacks on cryptocurrency systems especially if they become valuable because of to many fanatic believers like bitcoin has.
bitcoin is more like a speculative flagship that introduces a new technology. as soon as the hype flows down and the choice gets bigger people will rethink for what money they work for.
regards
if someone is interested joining a good new blockchain project than PN me cant tell more yet.