In long run, useless coins will fade away from market and only projects with strong growth will remain. There are too many altcoins and crypto project, it's difficult to choose a good project. You have to find and select a project with good team and good project for good returns. A project with a prototype product and strong team have more chances of success. But many of coins lack these things and will eventually die. However strong projects will give positive returns. So please be careful before investing in any coin and do complete research. Hence most of projects many not succeed and many of the coins may die but if you want good returns in crypto space then start analyzing and doing research. All useless cryptos that don't have the potential to grow will be dead and market will witness strong shift towards more useful projects.