I think it doesn't need to have a use case. It's low level enough that it's like asking what the use case is for cat. IE, it's a tool or even merely a component

I think it doesn't need to have a use case. It's low level enough that it's like asking what the use case is for cat. IE, it's a tool or even merely a component, or possibly a reference environment, not a product. (sure it's also kind of a product, it's obviously not litterally equivalent to cat, I'm just saying there is more than one way to look at it) Someone may or may not use it in anger for something some time, but things like this need to already exist before other people can come along later and stick the existing lego blocks together.