It makes little sense to me that the Roman Empire had their lorica segmantatas but in 13th century Europe they were still using mail despite armour made of metal plates existing a thousand years earlier
Adrian Goldsworthy's "The Complete Roman Army" has a pretty short good explanation of the decline of the Lorica Segmentata.
Basically the segmented plate cuirass declined due to maintenance issues. It was a complex design with a lot of small parts. Many of the small parts contained copper alloy, which caused corrosion issues with the iron plates. Taken together with a relatively modest improvement compared to chain mail (which always coexisted with the segmented cuirass) the Romans themselves largely abandoned the Lorica Segmentata by the 3rd century AD. Chainmail proved a cheaper solution, ultimately.