This morning I was talking about this with a buddy of mine.
Right now we have miners all over the world trying to solve this exponentially hard algorithm to earn their bitcoins. That is their incentive and that is what drives them to do so.
What happens when we remove that incentive to "mine" aka "verify transactions" on the blockchain? What I'm basically asking is what happens when we hit 21,000,000 bitcoins from the perspective of the miners?
From the calculations due to the difficulty increasing whenever each bitcoin is mined, it will be another one hundred year or so before the last bitcoin is mined in the entire world, I don't think that even Satoshi will be around to witness the milestone, I am certain that by then the current generation would have moved on to another cryptocurrency then.