Bitcoin is a protocol, not a product. Look at other Internet protocols that have achieved mass adoption: TCP/IP, DNS, SMTP, HTTPS, BGP, etc. Do we need another DNS protocol? It does what it is designed to do: map hostnames to IP addresses and vice versa and it does it so well, we don't really think about it. Does the world need another DNS hierarchy? You can create another one, sure, but it will not be used because DNS has all the users. Bitcoin allows for the transfer of value in a purely digital way. It works, it scales (side chain), and all the weak links have been strengthened because of merciless yet unsuccessful attacks. It has achieved mass adoption and the network effect. From a technical standpoint, you can create a second Bitcoin, but the world only needs one blockchain.