head to head
Neither is simply harder - they are hard in different places. Gran Turismo 2 demands more optimization; Grand Theft Auto V demands more reads.

Execution · Practiced Mastery
The PS1 driving opus where picking and tuning the right car for each event matters as much as driving it.

Execution · Practiced Mastery
Sandbox crime playground spanning shooting, driving, and a persistent online economy.
Gran Turismo 2 leans Execution (Practiced Mastery); Grand Theft Auto V leans Execution (Practiced Mastery).
Gran Turismo 2 leans clearly harder on execution.
Gran Turismo 2
Clean braking and lines matter, aided by forgiving AI.
Grand Theft Auto V
Driving and shooting demand decent inputs.
Grand Theft Auto V leans clearly harder on reads.
Gran Turismo 2
Rolling-start AI follows fixed pace scripts.
Grand Theft Auto V
Online PvP exists but mostly gear/positioning, not modeling.
Grand Theft Auto V leans a little harder on variance, though the gap is small.
Gran Turismo 2
Used car lot rotation is minor randomness.
Grand Theft Auto V
Some mission and lobby randomness.
Gran Turismo 2 leans clearly harder on optimization.
Gran Turismo 2
Car selection, tuning and prize-money routing dominate the career.
Grand Theft Auto V
Heists, money loops, builds learnable.
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.