head to head
Killing Floor 2 asks more than Grand Theft Auto V, and the gap is variance.

Execution · Practiced Mastery
Sandbox crime playground spanning shooting, driving, and a persistent online economy.

Execution · Practiced Mastery
Wave-based co-op horde shooter.
Grand Theft Auto V leans Execution (Practiced Mastery); Killing Floor 2 leans Execution (Practiced Mastery).
Killing Floor 2 leans clearly harder on execution.
Grand Theft Auto V
Driving and shooting demand decent inputs.
Killing Floor 2
Headshot-focused aim and weapon-switching
Grand Theft Auto V leans a little harder on reads, though the gap is small.
Grand Theft Auto V
Online PvP exists but mostly gear/positioning, not modeling.
Killing Floor 2
Scripted zeds, no adaptive opponent
Killing Floor 2 leans clearly harder on variance.
Grand Theft Auto V
Some mission and lobby randomness.
Killing Floor 2
Spawn waves and trader loot vary
Killing Floor 2 leans clearly harder on optimization.
Grand Theft Auto V
Heists, money loops, builds learnable.
Killing Floor 2
Perks, weapon synergies, money management
A matching score does not mean a matching test. Two games can both sit at 10 on execution and demand completely different things of you - which is why the reasoning above matters more than the number beside it.