head to head
Neither is meaningfully harder - they pose close to the same test. The widest gap is reads, and it is a single point.

Execution · Practiced Mastery
Arcade driving gated by a randomised upgrade-card progression economy.

Execution · Practiced Mastery
Street racer with stylized arcade handling.
Need for Speed: Payback leans Execution (Practiced Mastery); Need for Speed Unbound leans Execution (Practiced Mastery).
Same score on execution - which means the number cannot separate them. The difference is in what each one asks of you.
Need for Speed: Payback
Arcade handling and chase setpieces need decent hands
Need for Speed Unbound
Arcade drift and grip handling
Need for Speed Unbound leans a little harder on reads, though the gap is small.
Need for Speed: Payback
Cops and rivals run scripted pursuit logic
Need for Speed Unbound
Online lobbies, AI cops
Need for Speed: Payback leans a little harder on variance, though the gap is small.
Need for Speed: Payback
Speed-card upgrade rolls gate progression randomly
Need for Speed Unbound
Heat level and cop chase RNG
Same score on optimization - which means the number cannot separate them. The difference is in what each one asks of you.
Need for Speed: Payback
Grinding efficient builds and routes is the systems layer
Need for Speed Unbound
Car build, betting strategy, garage growth
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.