Yes, they have different uses cases. But one can easily see an arbitrage opportunity here for building an immortal database atop S3 (and other cloud services) for a lot less money. For $12,000 USD, I could store the same data in S3 for (at the very least) 445,217 years. (Using the example above.)
That makes the value proposition of the Ethereum blockchain as a data store a lot less attractive.
