For instance I'm conservative in economics (hear more capitalist) but reformist in morals (I like divorce, abortion and gay marriage). I vote for Macron therefore, who fits this. You can project his 2D stance on a 1D line and say he's a centrist, but he's left-morals, right-economics, so what is he at the "center" of ?
But I could be out of that matrix and say what matters is natural protection and vote for a green party who is either reformist or conservative in other policies but strongly focus on a single issue.
I don't understand american politics: it's like there's no variation of choice, just two sides of the same coins, role playing debate on pointless cultural issues without really having the power to reform or conserve.
Populist parties are more similar to american politics, they yell absurd nonsense at each other, accusing each other ad-hominem of various crass deeds, while distracting everyone from the real issue we need the state to solve, like decentralizing power away from the capital with the increase in mobility, organizing matrimony with the change in demographics, policing crime during various immigration crisis or all that stuff we can all discuss calmly and reach compromises over.
Politics is about managing transitions and changes in the population, and it's absurd to think the answer is bi-polar: republican or democrat, with a fallacy of the middle ground. Sometimes, it's just about softly following popular preference, sometimes it's about nudging the people to accept a necessary but difficult choice, sometimes it's about joining everyone in the middle because who cares.