Comment by Salgat

The biggest issue is that people underestimate how incredibly niche cryptocurrencies actually are. They solve one single issue, the double spending problem on truly anonymous transactions. For the vast majority of people, this isn't a problem they have. Smart contracts extend this functionality in novel ways, but the problem is still that the applications are incredibly niche. It's why people still use VISA or AliPay, it's why no Fortune 500 company relies on blockchains for its critical infrastructure, and why all major smart contract usage is related to either crypto exchanges, gambling, or more cryptocurrencies (such as ERC-20 based ones on the Ethereum blockchain).