I tend to think after this, that "if it's a direct combat, it's Luffy!" Which means Luffy can only be legit defeated when theres extra stuff involved such as gag or plot-induced to hype enemies, dumb mistakes Luffy makes.
While in real situation without PIS, only indirect combat can defeat Luffy. Like ranged attacks, tactics AoE, or hax that bypasses or nullifies something Luffy has.
Afterall Kaidou the WSC himself said that the victor of this battle (Luffy vs Kaidou) is one step closer to PK, implying Luffy takes the WSC status from Kaidou by defeating him. Its a direct milestone for Luffy.