The density of the base is the primary factor in wax penetration.
Structure .... those tiny grooves or pattern ... breaks the suction effect of the water that forms from the compression between snow and ski.
The example you see constantly used is the pane of glass on a wet flat surface ....
Especially critical when the snow is saturated during spring conditions but even then on some flats or easy pitches .... I watched the group ahead of me try to get speed to make it across a flat .... two inches of powder over wet base and temps were rising fast toward the upper 50's .... they tried to get speed on the pitch but when they hit the flat each and every one of them flew out of their bindings .... we noted this and rode across on our edges; there are some days when you'd have to use a chain saw to get enough structure to get through junk like that. On that day, knowing the conditions, I used a fluro & graphite combo wax and brushed it well to open the structure as much as possible but you could feel the skis getting slower and slower as the temp climbed.