There are a lot of altcoins and I am really curious why people buy them. Is there any worth of altcoin? Why not using only bitcoin? What's the future of altcoins?
The primary goal of an altcoin is to do things that BTC can't. LTC had a smaller block generation time and implemented Segregate Witness. ETH has the smart contracts feature and the ethereum virtual machine, that allows a greater number of instructions to the network. Other altcoins have better anonymous features. So, the alt worth comes from what who uses them thinks about this features.