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

Execution · Practiced Mastery
A kart-style racer about drifting and using items on family-friendly tracks.

Execution · Practiced Mastery
Accessible car control amid demolition chaos rather than precision racing.
Cars 3: Driven to Win leans Execution (Practiced Mastery); Dirt Showdown leans Execution (Practiced Mastery).
Dirt Showdown leans a little harder on execution, though the gap is small.
Cars 3: Driven to Win
drifting and item-timing control
Dirt Showdown
Drifting, boosting and ramming need solid car control
Dirt Showdown leans a little harder on reads, though the gap is small.
Cars 3: Driven to Win
minimal, mostly AI opponents
Dirt Showdown
Demolition modes reward predicting human movement a little
Same score on variance - which means the number cannot separate them. The difference is in what each one asks of you.
Cars 3: Driven to Win
item pickups and track hazard randomness
Dirt Showdown
Crash physics and pack chaos add randomness
Same score on optimization - which means the number cannot separate them. The difference is in what each one asks of you.
Cars 3: Driven to Win
vehicle upgrades and track knowledge
Dirt Showdown
Event types and boost routes are quickly 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.