Why is the view of the homepage different on every device?

The user interface should be equally clear and tidy on all screen sizes. For optimal use on smaller displays, the menu can be found via the popular hamburger menu icon. Furthermore, every user has the opportunity to individually customise the homescreen for every device (and every family member). For example:

A) Two users, one system: Each user can design the homescreen according to their own needs and preferences

B) One tablet for at home (switching on the TV in the evening) vs. a mobile for out and about (did I close the window?)