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.

Optimization · Practiced Mastery
Refined loot shooter with skill-tree builds.

Execution · Twitch Chaos
Dodging bullets while leveraging encyclopedic item knowledge against heavy run RNG.
Borderlands 3 leans Optimization (Practiced Mastery); The Binding of Isaac: Repentance leans Execution (Twitch Chaos).
The Binding of Isaac: Repentance leans a little harder on execution, though the gap is small.
Borderlands 3
Tighter gunplay than predecessors
The Binding of Isaac: Repentance
Dodging dense bullet patterns while aiming is constant pressure
Borderlands 3 leans a little harder on reads, though the gap is small.
Borderlands 3
Enemies scripted, no adaptive opponent
The Binding of Isaac: Repentance
Enemies are random or scripted, never modelling you
The Binding of Isaac: Repentance leans a little harder on variance, though the gap is small.
Borderlands 3
Weapon rolls and anointments randomize
The Binding of Isaac: Repentance
Item pools and room rolls reshape every run
Borderlands 3 leans a little harder on optimization, though the gap is small.
Borderlands 3
Skill trees, anointments, gear math deep
The Binding of Isaac: Repentance
Knowing hundreds of item synergies converts RNG into wins
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.