Actually it reinforces that the idea actually is the easiest part of the equation. Execution is the key and the winners are the ones who executed the best. You can't compare Webvan to Amazon.
Amazon ended up owning and operating Webvan.com.[1] The people who developed Webvan went on to develop Amazon Fresh.[2] The founder of Kiva Robotics, which was acquired by Amazon, was from Webvan. Amazon's grocery business is directly descended from Webvan.
Yes, it was a descendent. Instacart is a descendent of Webvan too. The idea is the same but Amazon already had preexisting technology and market dominance. You can't compare Webvan to Amazon.
That might be a factor, but given that they all failed at about the same time I think there's a good chance that timing is just as important. Adding billions of people to the internet and mass adoption of smartphones may have been necessary precursors to the success of Amazon/Facebook/Google/Uber.
