[Transactions] enabled the development of systems called databases, which can reliably maintain the state of complex data structures across incessant read and write operations as well as some level of hardware failures.
This is interesting. It suggests to me that either the author is using a nonstandard or outdated definition of "database" or that a denotation-fundamental tenet of database implementation, transactions, has been left for dead by the side of the road by many modern "database" projects.
Regardless, this is a great and informative piece.