Best Explanation of the benefits of Ethereum:The core value proposition of Ethereum can be summarized with a single word: Synergy.
To give an example, just at launch Maker is going to integrate and thus synergize with at least this list of other Ethereum projects:
Augur - We give them a stable store of value, they give us users. We can also use their token as collateral for the Dai.
Slock - We use their product, the Ethereum Computer, as an easily distributed plug-and-play server to run our Keeper daemon which provides us decentralized price feeds and trading bots (meaning better Dai liquidity), we also give them a stable store of value, and can use their DAO token as collateral for the Dai.
EtherEx - We provide a stable store of value to allow for decentralized ETH speculation directly on the Ethereum blockchain using their service (The combination of our CDP system + EtherEx even allows for decentralized margin trading!), and in turn we get better access to liquidity and and a platform for raising money without having to require KYC and other user annoyances.
Digix - We can use their gold token as collateral for the Dai, increasing the collateral diversity with non-cryptocurrency assets.
Oraclize - We use their service as an additional layer of secure price feeds to make sure our system is robust and cannot easily be attacked through its oracle mechanisms, and in return we provide them with income that we earn from providing a better secured Dai.
Colony - We use their service to organize our army of community volunteers, ensuring people who do work for Maker gets paid accordingly even when it's on a decentralized ad hoc basis. We can also use their token as collateral for the Dai.
Otonomos - We use their service to allow us to use real world company stock as collateral for the Dai, which enables us to offer business credit as well as further diversify the collateral portfolio of the Dai with non-cryptocurrency assets.
It is the permissionless and turing-completeness of Ethereum that allows all of these projects to seamlessly integrate with each other as first class citizens, increasing the value and utility of each other, because we all write to the same virtual machine and use the same language and the same standards.
Each project in the list above becomes a multiplier on the existing value of our system, resulting in exponential, rather than linear gains, for every new project that integrates with the others. Similarly every time any one of the above mentioned projects gains a new user or somehow grows in size, it ripples through the list and positively effects every other project in one way or another. Another huge advantage is that all of the integrations and synergies listed above require zero direct interaction or collaboration between the projects - it just emerges by itself due to the open source nature and streamlined standards of Ethereum. Of course in most cases there is still direct collaboration between the projects in this early stage of the ecosystem, but it's still important to note that this isn't a requirement - this will become a huge advantage once the network starts to really scale.
The result of this inherent synergy is an unbeatable network effect in accordance with Metcalfe's law. Every time a VC or a banker asks me which blockchains are interesting to look at in the industry, I tell them the same thing: Ethereum has already won. It has reached critical mass and become what can best be described as an unstoppable, ever growing snowball.
Another way to put it is if we decided to build Maker on a different blockchain, we'd have significantly less users and liquidity, and would have to spend a lot more resources on building things that others have already built for us to use as first class citizens on Ethereum, and due to those factors, we'd most likely be dead or dying at this point.