CSS2 (from 10 years ago) is equal in power to HTML tables. (The display:table-* properties are based directly on the layout model of HTML tables. For better or worse - they are also somewhat underspecified like HTML tables was.)
These new proposals are much more powerful. Most notably they allow you to visually place elements in a grid independent of the source-order. CSS2 (and HTML table markup) does not allow that, ie. visually adjacent cells must also be adjacent in the HTML.
These new proposals are much more powerful. Most notably they allow you to visually place elements in a grid independent of the source-order. CSS2 (and HTML table markup) does not allow that, ie. visually adjacent cells must also be adjacent in the HTML.