head to head
Neither is simply harder - they are hard in different places. Portal demands more execution; Raft demands more variance.

Optimization · Pure Optimization
The portal-gun puzzle game whose solutions are everything.

Optimization · Pure Optimization
Growing a floating base by solving resource chains and research order against scripted ocean threats.
Portal leans Optimization (Pure Optimization); Raft leans Optimization (Pure Optimization).
Portal leans clearly harder on execution.
Portal
Portal placement timing modest.
Raft
Shark hook-attacks require minimal timing
Same score on reads - which means the number cannot separate them. The difference is in what each one asks of you.
Portal
No adversary modeling player.
Raft
Shark and seagull AI are scripted with no player modelling
Raft leans clearly harder on variance.
Portal
Deterministic chambers; no randomness.
Raft
Island loot tables and resource drift introduce randomness
Portal leans a little harder on optimization, though the gap is small.
Portal
Pure puzzle-solving optimization.
Raft
Raft expansion, food chains, and research order are solvable systems
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.