Why build a milk stash?

I keep seeing videos about how to produce more milk, how to increase your supply, and that sort of thing which makes sense, to me. But I’m also seeing mamas stockpiling these HUGE collections of breastmilk...like to the point that it seems excessive because the whole entire freezer is full of milk and no one is talking about why they need that much, just this overwhelming feeling of “Need to have a HUGE stash” it’s honestly kind of intimidating to me. Can someone explain why it might be a good idea to have that much milk on hand or is this just mamas being over prepared? I genuinely feel like I’m missing something obvious. Please help

*Editing to say thank you for all the replies, that makes more sense to me now. Idk this was just something my anxiety brain picked up on. I was stressing out because I don’t know if I can make that much.