head to head
iRacing asks more than Splatoon 2, and the gap is execution.

Execution · Practiced Mastery
Hardcore online racing sim with PvP wheel duels.

Execution · Practiced Mastery
A team shooter where aim and positioning against human opponents controls the map.
iRacing leans Execution (Practiced Mastery); Splatoon 2 leans Execution (Practiced Mastery).
iRacing leans clearly harder on execution.
iRacing
Brutally precise wheel inputs required
Splatoon 2
aim and movement decide ink battles
Splatoon 2 leans a little harder on reads, though the gap is small.
iRacing
Serious wheel-to-wheel racing vs humans
Splatoon 2
predicting human opponent positioning
Same score on variance - which means the number cannot separate them. The difference is in what each one asks of you.
iRacing
Weather, tire wear, mechanical variance
Splatoon 2
weapon and map rotation randomness
iRacing leans a little harder on optimization, though the gap is small.
iRacing
Setup, strategy, iRating progression
Splatoon 2
loadout and turf strategy solvable
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.