Complex technology ecosystems, in which there are many producers and consumers of data, tend to be very resistant to change. The producers of the data need to keep producing it in the "old" format as long as there are still consumers that need it; there is reduced pressure to innovate at the consumer end because the producers are still producing the old format data.
Until very recently, the major stock exchanges in the US were still maintaining, in parallel with the more modern stuff, the electromechanical systems that transmitted stock quotes in a format readable by the iconic ticker tape printer. The printers themselves were long ago junked or sold as antiques, but there were other systems around that still read the data in that format.
