Benefits Over Autoclaving / Retort
In autoclaves the exposure of the media to damaging heat is extremely long (minimum of 40 minutes, but normally upwards of 1 hour). Additionally, this exposure to heat (and therefore quality) varies from batch to batch and within a batch due to the required penetration of heat to the center of the containers.
Larger containers or batches take longer to get their center to sterilization temperature than small containers or batches. Thus the products have to be formulated so that they retain their required functionality in based on the longest exposure to heat.