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
VR rhythm game about slicing color-coded blocks to music with lightsabers.

Execution · Pure Mechanics
A pure physical-execution trainer - playing a real guitar accurately on time.
Beat Saber leans Execution (Pure Mechanics); Rocksmith 2014 leans Execution (Pure Mechanics).
Beat Saber leans a little harder on execution, though the gap is small.
Beat Saber
Pure full-body rhythm precision at speed
Rocksmith 2014
Real fretting and picking accuracy is literally the whole game
Same score on reads - which means the number cannot separate them. The difference is in what each one asks of you.
Beat Saber
No opponent of any kind
Rocksmith 2014
No opponent, only the song
Same score on variance - which means the number cannot separate them. The difference is in what each one asks of you.
Beat Saber
Patterns are fully known and fixed
Rocksmith 2014
Charts are fully known in advance
Same score on optimization - which means the number cannot separate them. The difference is in what each one asks of you.
Beat Saber
Swing-angle scoring technique and map memorization
Rocksmith 2014
Practice scheduling helps but solves nothing for your hands
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.