head to head
Neither is simply harder - they are hard in different places. Borderlands 2 demands more execution; South Park: Phone Destroyer demands more reads.

Optimization · Systems & Chaos
Loot-shooter RPG built on gear chasing.

Optimization · Systems & Chaos
Deckbuilding math and draw luck with a layer of live opponent prediction.
Borderlands 2 leans Optimization (Systems & Chaos); South Park: Phone Destroyer leans Optimization (Systems & Chaos).
Borderlands 2 leans clearly harder on execution.
Borderlands 2
Aim matters but generous hit feel
South Park: Phone Destroyer
Card placement timing matters slightly under real-time pressure
South Park: Phone Destroyer leans clearly harder on reads.
Borderlands 2
Enemies are scripted loot fodder
South Park: Phone Destroyer
Human PvP rewards anticipating opponent card plays and counters
Same score on variance - which means the number cannot separate them. The difference is in what each one asks of you.
Borderlands 2
Procedurally generated weapon drops vary
South Park: Phone Destroyer
Card draws and gacha-driven collections dominate matchups
Borderlands 2 leans a little harder on optimization, though the gap is small.
Borderlands 2
Skill trees and gear math heavily solved
South Park: Phone Destroyer
Deck construction and energy efficiency are the solvable core
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.