I have absolutely no worries concerning the very idea of cryptocurrency and its underlying fundamental of blockchain technology. The only worrying evolution is the expanse of centralized exchanges and close sourced applications. Crypto will have to go back to its cypherpunk roots - focus on privacy, censorship resistance, decentralization, open source. Unfortunately the spread of closed source, censorable and centralized solutions poses a significant danger that in the worst scenario people might get all their funds blocked or stolen. Personally I don't worry about the future of crypto currency, I only worry about the security of my funds and I try to minimize threats by staying away from centralized exchanges and closed source wallets, and using open source alternatives like HODLER multiwallet and decentralized exchanges.