This Misunderstood Moments in History: The Spartan Myth video claims that a lot of how we view the Spartans today is exaggerated or just wrong. He claims that he uses the latest in research to try and undo the myth. He lists some sources in the video's notes. Is this video accurate? A lot of people in the comments don't seem to think so.
I did try searching for "sparta" in this sub prior to asking but I keep getting a "Sorry, there were no post results for “" " message.
I think this thread/podcast episode featuring /u/Iphikrates will interest you: https://www.reddit.com/r/AskHistorians/comments/90ha3e/askhistorians_podcast_116_debunking_300s_battle/?utm_source=reddit-android
Bear in mind, not many people are willing to sit through a video to see if it's accurate, so I recommend typing out any specific claims that you wonder about.