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 · Twitch Chaos
Kart racing blending drift execution with item RNG and pack positioning.

Execution · Competitive PvP
Battle-royale gunfights testing aim and positioning reads under loot randomness.
Mario Kart World leans Execution (Twitch Chaos); Mini Royale leans Execution (Competitive PvP).
Mini Royale leans a little harder on execution, though the gap is small.
Mario Kart World
Drift charging, rail grinding and shortcut precision reward hands
Mini Royale
Aimbot would dominate every toy-soldier firefight
Mini Royale leans a little harder on reads, though the gap is small.
Mario Kart World
Human racers bait items and contest lines in knockouts
Mini Royale
Fifty human players to predict in positioning and pushes
Mario Kart World leans a little harder on variance, though the gap is small.
Mario Kart World
Item rolls and rubber-banding scramble any single race
Mini Royale
Loot spawns and circle placement shake up every match
Mario Kart World leans a little harder on optimization, though the gap is small.
Mario Kart World
Course knowledge, shortcuts and item management converge with study
Mini Royale
Drop spots and loadout knowledge form a thin solvable layer
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.