From https://yum-asia.com/uk/product/panda-mini-advanced-fuzzy-logic-ceramic-rice-cooker/

Fuzzy logic are good at predicting cooking results but it requires some time to calculate the time needed to cook something. This is because of several factors that it needs to figure out such as ambient room temperature, starting bowl temperature of contents, what you are cooking and other various factors.

As for the why - read https://www.atlasobscura.com/articles/rice-cooker-history