Not sure if you have actually used the internet over the last 20 years, but usually when an idea comes along and it gets a decent following it isn't just copied, it's copied a LOT. It is inevitable that something Bitcoin inspired is going to come along.
Bitcoin is actually a pretty simple concept (although you don't appear to get it). Its value is mostly not in the implementation of the idea but the community and the infrastructure surrounding it. A new entrant can't just one day decide to unveil a shiny new decentralized currency.