well, sure if you read the rest of the article you’ll find that you may be right
This reason is nonsense. The Romans didn’t have war chariots - theirs was an infantry army (Republic and Principate). About the time of the Dominate (or perhaps the Third Century crisis), cavalry began to become more important.
War chariots are not particularly effective weapons, which is perhaps why they fell out of disfavor with the fall of the Persians to Alexander the Great (fourth century BC).
Let us note that chariots would be a particularly uncomfortable mode of passenger transportation. Imagine standing in a jolting chariot for more than a few minutes.