The U.S. reaping these benefits from their two party system is confounded by the primaries. The "centre" of each primary is with respect to the party platform, not the general population.

Presidential candidates' optimal strategy is to be centre of the party base in primaries, then centre of the entire country in the general election. (And they have to do this while avoiding accusations of flip flopping.)

(And there are other confounders that apply regardless of voting system. Nobody involved is working with perfect information and nobody is a perfectly rational actor.)