This is a great blogpost on feature stores https://www.ethanrosenthal.com/2021/02/03/feature-stores-self-service/

Again, feature stores and delta lake are different technologies for different things. Our feature store does need to store data, and that's where delta lake is amazing. Delta Lake doesn't integrate with mlflow like our feature store does. The feature store does a better job of tracking lineage. The FS doesn't have a selling point, it's free to use in the Machine Learning Persona!