MVC is not bad, but it is not a silver bullet. Calling MVC an ultimate solution to UI is oversimplification. Just looking at the steps you listed I can ask:
How do you collect all notifications on step 2 to fire them on step 3 such that UI does not re-render itself too much? E.g. updating a title of each item in a list of 100 items should not trigger 100 renders. Or 100 layout calculations (which I think is harder to avoid).
How do you deal with situations where on step 4 UI triggers an event that your model happens to listen and the cycle repeats while killing performance?
Because you rely on events how do you avoid “event hell”? That is, a situation when an event handler triggers a change that triggers another event handler that triggers a change and so on. Sometimes it is scrolling or typing, sometimes it is parts of the model subscribed to each other bubbling events to UI.
How do you collect all notifications on step 2 to fire them on step 3 such that UI does not re-render itself too much? E.g. updating a title of each item in a list of 100 items should not trigger 100 renders. Or 100 layout calculations (which I think is harder to avoid).
How do you deal with situations where on step 4 UI triggers an event that your model happens to listen and the cycle repeats while killing performance?
Because you rely on events how do you avoid “event hell”? That is, a situation when an event handler triggers a change that triggers another event handler that triggers a change and so on. Sometimes it is scrolling or typing, sometimes it is parts of the model subscribed to each other bubbling events to UI.