There were hardly a dozen alt-coins before Ethereum. I mentioned specifically Ethereum because it was Ethereum that introduced a Turing complete virtual machine that allowed people to execute code in Blockchain. Before Ethereum came into the picture people used Blockchain only for storing value. So Ethereum was a game changer and it is only 3 years old.

Ethereum developers are currently working hard on making Ethereum more scalable. It cant definitely power the web anytime soon but its getting better and better. Read about Sharding, Plasma, Raiden etc if you are interested.