I do think though that the use cases for lots of local storage is deminshing quickly with the rise of cloud services. However, I generally buy more than I think I need, and the pricing of the current Pro models made the jump from 64 to 256 kind of a no-brainer. I doubt that I will ever come close to using 256, but it is nice to have to not worry about what to store locally and what not to.
That's fair, but I still feel it's somewhat situational. If you tend to travel in areas without free public Wifi, you might need Cellular data, and then there's the cost of cellular data, which also depends on the region you're in.
Buy what suits your needs of course, but there are use cases for large amounts of storage. However, I will admit to be annoyed that USB3-speed transfers are still not easily available for the iPad.