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.

Optimization · Pure Optimization
Renovation sim about cleaning and flipping houses.

Optimization · Pure Optimization
A life simulator where planning schedules and needs against a solvable system is the real game.
House Flipper leans Optimization (Pure Optimization); The Sims 4 leans Optimization (Pure Optimization).
House Flipper leans a little harder on execution, though the gap is small.
House Flipper
Click-and-drag cleaning and placement
The Sims 4
no physical skill ceiling at all
Same score on reads - which means the number cannot separate them. The difference is in what each one asks of you.
House Flipper
No adaptive opponents
The Sims 4
no opponents, simulated NPCs only
Same score on variance - which means the number cannot separate them. The difference is in what each one asks of you.
House Flipper
Light job variety
The Sims 4
minor random events and needs decay
House Flipper leans a little harder on optimization, though the gap is small.
House Flipper
Renovation routing, budget, profit margins
The Sims 4
life and career system optimization dominant
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.