Sharp skis are necessary for good control otherwise you're just sliding around. Snow and Ice aren't the only things you ski over as there is a ton of dirt and other debris mixed in. Sometimes you get rocks and pebbles near trail edges. Heck, spring skiing will put you on trails with thin snow cover in addition to patches of grass and dirt that will destroy your skis (fun fact: hitting grass at speed is NOT fun - instant stop.)
My father was also of the opinion that wax was a scam as he stated it would likely wear off in the first few runs. The idea was it filled in the scratches on the ski bottoms leaving a flatter surface. Maybe it works. maybe it doesn't. I always enjoyed watching the guys in the ski shops apply it by taking a slice of wax and then using a clothes iron, melt it like a pat of butter along the bottom.
We could talk for pages about wax. Your father is partly right, it does wear off quickly, especially if you apply it correctly.
I'd say wax is important in that it prevents the base from oxidizing. A dried out base is more difficult to turn and slower.
Structure (small grooves in the base) will make you a second faster)
Wearing a race suit vs a normal tight coat will make you two seconds faster.
Proper setup edges vs no tune rounded edges will make you 5-6 seconds faster and with much lower chances of dsq.
The type of wax is much less important. In a slalom race, choosing the best wax vs a less perfect type might only improve you by 0.02 seconds on a sixty second long race.
I guess that was the issue, we were casual skiers who just enjoyed the runs so when they offered wax, it was of no use to us so may father refused. This was at the mountain ski shop so you know they pushed everything they could.
My father was also of the opinion that wax was a scam as he stated it would likely wear off in the first few runs. The idea was it filled in the scratches on the ski bottoms leaving a flatter surface. Maybe it works. maybe it doesn't. I always enjoyed watching the guys in the ski shops apply it by taking a slice of wax and then using a clothes iron, melt it like a pat of butter along the bottom.