head to head
Neither is harder. They score identically on all four axes, so the difference between them is in kind, not degree.

Execution · Grand Arena
The battle royale archetype: loot, rotate, and outlast 99 opponents inside a shrinking circle.

Execution · Grand Arena
Battle royale survival blending aim, rotation planning, and heavy circle-and-loot RNG.
PlayerUnknown's Battlegrounds leans Execution (Grand Arena); PUBG Mobile leans Execution (Grand Arena).
Same score on execution - which means the number cannot separate them. The difference is in what each one asks of you.
PlayerUnknown's Battlegrounds
Recoil control and long-range ballistics
PUBG Mobile
Touchscreen aim and recoil control set the ceiling
Same score on reads - which means the number cannot separate them. The difference is in what each one asks of you.
PlayerUnknown's Battlegrounds
99 humans rotating and ambushing adaptively
PUBG Mobile
Outguessing rotations and third-party timing of human squads
Same score on variance - which means the number cannot separate them. The difference is in what each one asks of you.
PlayerUnknown's Battlegrounds
Loot spawns and circle placement shape every match
PUBG Mobile
Circle placement, loot and drop locations dominate single matches
Same score on optimization - which means the number cannot separate them. The difference is in what each one asks of you.
PlayerUnknown's Battlegrounds
Zone rotations and positioning theory are learnable
PUBG Mobile
Zone rotation theory and loadout priorities are well mapped
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.