The product has a very targeted user cohort, and typically a product designer won't be familiar with them unless you had a similar background in Data Science. Even before joining, I was a little unsure whether I could design something for them.
So, even though it's not "mandatory" - I feel I need to invest extra time to learn about this field which is packed with numbers, figures, and jargon. If I were very time-poor or had something to do after 5 PM, this could easily become a burden for my work-life balance.