World class, for me, is being in the top two in the world in your position at that current time.
When with us:
Kante? Yes, world class DM.
Mahrez? No, multiple players better at the time.
Vardy? No, same as above.
Riccy P? For a brief period I’d say he was world class, brief.
People suggesting Vardy and Mahrez clearly define world class more broadly.