I realize that the difference is that the items are laid out horizontally, i.e. photos 1-2-3-4 are all across the top, whereas with vertical flexboxes items 1-2-3-4 would end up in the first column (or you'd have to rearrange your divs taking the flexbox layout into account, which is often impractical).
But the gain from CSS Grid Lanes is not immediately obvious from looking at the first photo, as it's so very similar to the old "left is flexbox, right is grid" examples from when Grid was new.
+-------+------------+ +-------+------------+ +-------+------------+
| state | population | | state | population | | state | population |
+=======+============+ +=======+============+ +=======+============+
| AL | .... | | DE | .... | | MI | .... |
| AK | .... | | FL | ..... | | MN | .... |
| | | | | | | | |
I need to put the heading at the top. It needs to make the heading sticky. As it is those, AFAIK there is no "easy" solution for this