You are accurate in that fish sauce is the original but people switched to shrimp sauce because it was less pungent. I think when you salt the veggies and then

You are accurate in that fish sauce is the original but people switched to shrimp sauce because it was less pungent. I think when you salt the veggies and then coat it with a mix of garlic pepper paste and wait for fermentation to occur, flavor is produced. Like if you ate a newly seasoned Kimchi you can tell it's not ripe until it eventually develops its flavor after fermentation has taken place.