More possessions can add to our happiness, but only to a point. You’d be happier living in a small house than a cardboard box, but you might not be any happier living in a mansion than in that small house.
You might. But it would also depend on what you’d have to sacrifice to get it: time, health, relationships, integrity, or peace of mind.
How much do you really need? What’s enough?
Happiness is as much about what we don’t need as it is about what we do.