I think mining will be stopped in future. Because they will be more and more coins who wouldnt be mined anymore, because it just needs to much power and to much eelectricity. YOu see there are several coins who work with prrof of stake and it works very good. So instead of mining with the high hash power, you can mine with your regular pc and your wallet, which uses a much few electricity. Also the tangle system from iota is much better for the enviroment!