I can think of several reasons:

    - Reading information from utility providers which few people are able to measure locally
    - You want to integrate with some system which is physically outside your home, like I don't know a smart mailbox if those exist (and god damnit now I want that...)
    - You are forced to because the product you have can't be controlled any other way and it's not feasible to replace it
    - A locally controllable version of X exists, but it's three times the price of one from vendor Y which requires a cloud integration