Ethereum? are u sure?...  I think if bitcoin is obsolete, then second place must be hardfork bitcoin that replaces it. ethereum is large with its platform but seems stagnant in numbers around that alone. This is my opinion but it seems that it isn't possible because as long as the world is still talking about bitcoin and its own users still put the bitcoin on the other coins bitcoin may not be obsolete. unless it is closed unilaterally (hopefully not).