the simplest answer is usually the right one
everything
because that's what they're ancestors used, their "traditional"
You definitely have no clue what you're talking about.
The highest performance blade steel in almost every aspect except corrosion resistance are all carbon/carbon alloy steel.
Best edge holding at cutting robe : K390
Cutting competition king : M4
Toughest : 3V
Best edge stability/sharpness/well balance: 52100