The main appeal is the ability to make transactions without intermediaries. The problem is that most people have as the only interest to get richer and richer and there will be always other people happy to sell them that dream.. For a fee. These are the vastmajorituy of the people in cryptocurrencies, but that doesn't disreguard the power and utility of the technology. It's easy to shit on the tool, but the real problem is the greed-driven society we live in.