These provide you with skill points and unlock new alchemy recipes.Furthermore, the “Ancient Treasures DLC” is not needed to find the DLC treasures. The treasure chests contain many books, too. Also keep one set of fine clothes that boost your charisma, it will come in handy in some dialogues.
It’s recommended that you keep the best armor pieces and sell the rest. Each treasure contains powerful armor parts and money. It’s also great for finding the best armor early in the game. Finding all treasures is the fastest way to get money in Kingdom Come Deliverance.