head to head
Grand Theft Auto V asks more than Luigi's Mansion 3, and the gap is reads.

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

Optimization · Practiced Mastery
Haunted-hotel adventure climbing themed floors with vacuum and goo clone.
Grand Theft Auto V leans Execution (Practiced Mastery); Luigi's Mansion 3 leans Optimization (Practiced Mastery).
Grand Theft Auto V leans a little harder on execution, though the gap is small.
Grand Theft Auto V
Driving and shooting demand decent inputs.
Luigi's Mansion 3
Slam combos and boss-dodge timing
Grand Theft Auto V leans clearly harder on reads.
Grand Theft Auto V
Online PvP exists but mostly gear/positioning, not modeling.
Luigi's Mansion 3
Floor bosses run fixed scripts
Grand Theft Auto V leans a little harder on variance, though the gap is small.
Grand Theft Auto V
Some mission and lobby randomness.
Luigi's Mansion 3
Hotel floors are authored
Luigi's Mansion 3 leans a little harder on optimization, though the gap is small.
Grand Theft Auto V
Heists, money loops, builds learnable.
Luigi's Mansion 3
Gooigi puzzles and gem routes are solvable
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.