Ethereum is a great platform, but it's not designed to be a currency.
From p2pfoundation.
"One common concern about Ethereum is the issue of scalability. Like Bitcoin, Ethereum suffers from the flaw that every transaction needs to be processed by every node in the network. With Bitcoin, the size of the current blockchain rests at about 20 GB, growing by about 1 MB per hour. If the Bitcoin network were to process Visa's 2000 transactions per second, it would grow by 1 MB per three seconds (1 GB per hour, 8 TB per year). Ethereum is likely to suffer a similar growth pattern, worsened by the fact that there will be many applications on top of the Ethereum blockchain instead of just a currency as is the case with Bitcoin, but ameliorated by the fact that Ethereum full nodes need to store just the state instead of the entire blockchain history." (http://buyxpr.com/build/pdfs/EthereumWhitePaper.pdf)This is what evolution is addressing.
This is something that DASH has covered correct ?
Yes, Masternode operation is incentivized so as transaction volume increases the value of rewards to run more powerful nodes increases to offset the cost, meaning the network infrastructure scales with usage. Dash's design rationale in this area is to use economic incentives (a share of the block reward distributed equally amongst Masternode operators) to scale the network instead of reliance on Moore's law in the same way Bitcoin mining relies on economic incentives to secure the network rather than volunteerism.
Plus Masternode quorums mean you don't need every node in the network to partake in every action you want to do, therefore if Dash implements something like Ethereum's Turing complete scripting capability, the contract code wouldn't need to be executed by every node in the network, it could be delegated to subsets of nodes i.e. quorums, and could operate in near real-time rather than having to wait for the next block confirmation (state transition in Ethereum terms) by reusing the Instant X architecture.
There are also some new pruning methods in Evolution that Evan is working on that would reduce the blockchain size to help with scaling.