head to head
Neither is meaningfully harder - they pose close to the same test. The widest gap is reads, and it is a single point.

Reads · Competitive PvP
A platform fighter where edgeguards turn on reading the opponent.

Execution · Competitive PvP
KOF's jump to 3D visuals with a huge fifty-character launch roster.
Super Smash Bros. Ultimate leans Reads (Competitive PvP); The King of Fighters XIV leans Execution (Competitive PvP).
Same score on execution - which means the number cannot separate them. The difference is in what each one asks of you.
Super Smash Bros. Ultimate
Tech skill, edgeguards, and DI are mechanically heavy.
The King of Fighters XIV
Max mode confirms and hop pressure test hands
Super Smash Bros. Ultimate leans a little harder on reads, though the gap is small.
Super Smash Bros. Ultimate
Adaptive opponents drive ledge and platform mind games.
The King of Fighters XIV
Classic KOF human mixups demand continual reading
Super Smash Bros. Ultimate leans a little harder on variance, though the gap is small.
Super Smash Bros. Ultimate
Stage hazards and items if enabled.
The King of Fighters XIV
Deterministic 3v3 combat
Same score on optimization - which means the number cannot separate them. The difference is in what each one asks of you.
Super Smash Bros. Ultimate
Matchup knowledge and kill confirms are learnable.
The King of Fighters XIV
Team order and max-mode damage routes 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.