Yes there are several other cryptocurrencies that (at least attempt to) address this issue. Those solutions were disregarded as non-essential technical improvements, and any change to Bitcoin would bring instability. Now perhaps more people will see those as fundamentals to the currencies' goal.
You can see here many alternative coins and an estimated market cap:
A lot of altcoins came up as mere clones of another, pump-and-dump schemes, or with irrelevant or plain bad changes; but there were quite a few valid innovations. Bitcoin has barely changed in it's core protocol. I hope other projects get more exposure in the future (or Bitcoin becomes less afraid of change).
"You can't possibly get a good technology going without an enormous number of failures. It's a universal rule. If you look at bicycles, there were thousands of weird models built and tried before they found the one that really worked. You could never design a bicycle theoretically. Even now, after we've been building them for 100 years, it's very difficult to understand just why a bicycle works – it's even difficult to formulate it as a mathematical problem. But just by trial and error, we found out how to do it, and the error was essential." -- Freeman Dyson
You can see here many alternative coins and an estimated market cap:
http://coinmarketcap.com/
A lot of altcoins came up as mere clones of another, pump-and-dump schemes, or with irrelevant or plain bad changes; but there were quite a few valid innovations. Bitcoin has barely changed in it's core protocol. I hope other projects get more exposure in the future (or Bitcoin becomes less afraid of change).
"You can't possibly get a good technology going without an enormous number of failures. It's a universal rule. If you look at bicycles, there were thousands of weird models built and tried before they found the one that really worked. You could never design a bicycle theoretically. Even now, after we've been building them for 100 years, it's very difficult to understand just why a bicycle works – it's even difficult to formulate it as a mathematical problem. But just by trial and error, we found out how to do it, and the error was essential." -- Freeman Dyson