DO just happens to be cheaper than AWS for certain use cases, but they didn't get there by out competing on price alone, it ticks a lot of other boxes: it's easier and simpler to understand for a new developer looking to get started, you can calculate and anticipate usage costs with ease, etc. It's not just a good copy with better pricing, it brings something to the table.
Exactly. DO launched with great pricing, SSDs, and an attractive UI. If they launched with only one of those three we wouldn't be talking about them today.