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 · Pure Mechanics
Momentum-perfect platform racing spiced with item mind games against humans.

Execution · Competitive PvP
Movement-heavy shooting where map control and reading enemy pushes decide matches.
SpeedRunners leans Execution (Pure Mechanics); Splatoon 3 leans Execution (Competitive PvP).
SpeedRunners leans a little harder on execution, though the gap is small.
SpeedRunners
Grapple swings and boost timing at full speed decide races
Splatoon 3
Aim, squid movement and ink mobility decide engagements
Splatoon 3 leans a little harder on reads, though the gap is small.
SpeedRunners
Timing item throws against human racers' habits wins exchanges
Splatoon 3
Turf and ranked battles hinge on predicting adapting human squads
Same score on variance - which means the number cannot separate them. The difference is in what each one asks of you.
SpeedRunners
Item pickups add party-game chaos
Splatoon 3
Matchmaking and special timing add modest noise
Splatoon 3 leans a little harder on optimization, though the gap is small.
SpeedRunners
Optimal racing lines per track are learnable
Splatoon 3
Gear builds, weapon kits and map control patterns are studied
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.