I wouldn't say niche. B-trees and B+ trees with doubly linked lists connecting the leaf nodes are used in every major database server for indexes. Hash tables a

I wouldn't say niche. B-trees and B+ trees with doubly linked lists connecting the leaf nodes are used in every major database server for indexes. Hash tables are generally used by optimizers to handle unindexed data in queries. Doesn't make hash tables niche. > and is already at the point where frequently linearly copying kilobytes of arrays is almost always faster than using a linked list. That's only half the story. Sure reading arrays in sequential order is fast. What about inserting or deleting items within an array? What are the costs to having to constantly resize arrays? It is very expensive. At the end of the day, it's about finding the right data structure for the data and your needs.