[c-smile]

1. FlexBox breaks existing CSS Box model that mandates that dimensions of the element are defined by its width/height properties.

2. FlexBox introduces 12 (sic!) new properties in already overcrowded CSS property map. But as demonstrated by Sciter that can be achieved by just one property `flow` and flex units.

3. Flexbox and Grid are conflicting in the sense that the flexibility (as a feature) is defined in two different ways: separate properties (FlexBox) and 'fr' units (Grid) - overall CSS architecture becomes a zoo. Yet CSS has that famous 'auto' value that in some cases is just 1fr ( 1* in Sciter terms).

4. FlexBox is applied through 'display' property that is conceptually wrong. 'display' specifies how the element itself is replaced among its siblings but flexbox is rather about layout of element's children. These two entities are orthogonal. Example:

display:list-item; or display:table-cell; cannot be flexboxes. Just because of architectural specification error but physically nothing prevents <td> to use flexbox layout for their children.

5. Flexbox arrived too late. We started talking about the feature 12 years ago on www-style WG at W3C. And all these years Sciter already used flexibility (the must for desktop UI).

More on this: https://terrainformatica.com/2018/12/11/10-years-of-flexboxi...