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 · Practiced Mastery
The fastest mainline Souls, distilling the formula into aggressive boss duels.

Execution · Pure Mechanics
A demanding souls-like won by perfect-guard timing and weapon assembly.
Dark Souls III leans Execution (Practiced Mastery); Lies of P leans Execution (Pure Mechanics).
Lies of P leans a little harder on execution, though the gap is small.
Dark Souls III
fast roll timing against aggressive scripted bosses
Lies of P
Perfect-guard timing window punishes errors
Same score on reads - which means the number cannot separate them. The difference is in what each one asks of you.
Dark Souls III
PvP invasions exist but are optional
Lies of P
Scripted bosses, no adaptation
Same score on variance - which means the number cannot separate them. The difference is in what each one asks of you.
Dark Souls III
fixed encounters converge after first sight
Lies of P
Minor weapon assembly variance
Dark Souls III leans a little harder on optimization, though the gap is small.
Dark Souls III
movesets and builds are fully mappable
Lies of P
Weapon assembly and P-organ builds reward planning
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.