head to head
Neither is simply harder - they are hard in different places. Grand Theft Auto V demands more reads; Persona 5 Strikers demands more optimization.

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

Optimization · Practiced Mastery
Action-RPG sequel turning Persona 5's turn battles into musou-style real-time brawls.
Grand Theft Auto V leans Execution (Practiced Mastery); Persona 5 Strikers leans Optimization (Practiced Mastery).
Same score on execution - which means the number cannot separate them. The difference is in what each one asks of you.
Grand Theft Auto V
Driving and shooting demand decent inputs.
Persona 5 Strikers
Real-time musou combos and dodge timing
Grand Theft Auto V leans clearly harder on reads.
Grand Theft Auto V
Online PvP exists but mostly gear/positioning, not modeling.
Persona 5 Strikers
Enemies swarm on scripts
Same score on variance - which means the number cannot separate them. The difference is in what each one asks of you.
Grand Theft Auto V
Some mission and lobby randomness.
Persona 5 Strikers
Minor drop and request randomness
Persona 5 Strikers leans clearly harder on optimization.
Grand Theft Auto V
Heists, money loops, builds learnable.
Persona 5 Strikers
Weakness exploitation and bond skill investment
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.