When this approach was popularised in early 2000's the speed in which innovation happened was slower so maintaining the moat is more difficult.

That being said, each business that has created success in blue ocean strategies has been focused on a specific areas of the customer value chain such as making EVs accessible or music streaming a viable option to itunes and built from there.

I think if companies focus on customer value they will win a market - to maintain it, it is how the build a connected network to serve the customer, this reduces a single failure point in the offering such as an innovative piece of technology, rather it is a set of intricate systems and processes. Amazon are a great example of this. Its not 1 app or product but a set of processes as well