Knowing the current size of a view or the currently active breakpoint of a container would be extremely beneficial in many situations.

Imagine a flex repeater or container with child views which have a variable height. E.g. on smaller screens they align their elements vertically, on bigger screens horizontally. The container / repeater is set to column so that the child views are stacked vertically.

To make that setup scale properly we need to set a minimum height for the elements in the repeater (basis property).

This size is variable and depends on the currently active break point of the child views (and therefore indirectly on the size of the repeater itself). None of this information is available.

The viewport which has been exposed in current versions is not useful in this case, because the repeater / container size is different from the global viewport size.

As stated in this forum post, the reason for not exposing the breakpoints is because it can be misused to create infinite loops.

I do not really see this as an argument, since there are many other ways for a programmers to create infinite loops if they are not aware of what they are doing. But it would not even be necessary to actively influence the breakpoints (which does not make sense).

Only having read access to this information would already be extremely beneficial to resolve a lot of challenges which are barely solvable right now. Knowing the current size of a view / component would also solve the problem.