What happens when all bitcoins are mined and competition for bitcoin mining decreases because there are only transaction fees? What then? Bitcoin may run into serious complications 40 years down the line from now. This means the longevity of bitcoin network is at stake. Once the hashing rate decreases then, any government/ corporation can jump in and perform a 51% attack.
It is going to be over 100 years before the final coins are mined. The year 2140.