head to head
Guild Wars 2 asks more than Grand Theft Auto V, and the gap is optimization.

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

Optimization · Practiced Mastery
Active dodge-heavy combat with a deep build system, tested against both scripted content and human opponents.
Grand Theft Auto V leans Execution (Practiced Mastery); Guild Wars 2 leans Optimization (Practiced Mastery).
Guild Wars 2 leans a little harder on execution, though the gap is small.
Grand Theft Auto V
Driving and shooting demand decent inputs.
Guild Wars 2
Dodge timing and active combat define moment-to-moment play
Guild Wars 2 leans clearly harder on reads.
Grand Theft Auto V
Online PvP exists but mostly gear/positioning, not modeling.
Guild Wars 2
WvW and structured PvP feature real adaptive opponents
Guild Wars 2 leans a little harder on variance, though the gap is small.
Grand Theft Auto V
Some mission and lobby randomness.
Guild Wars 2
Loot RNG is present but secondary to skill expression
Guild Wars 2 leans clearly harder on optimization.
Grand Theft Auto V
Heists, money loops, builds learnable.
Guild Wars 2
Build crafting and rotation theory-crafting reward deep analysis
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.