That’s how, for example, the British system works (but even it has some features that make it quite different in practice from the American one, for example the

That’s how, for example, the British system works (but even it has some features that make it quite different in practice from the American one, for example the head of government needing to maintain the confidence of parliament). It’s not how most of the actually well-run parliamentary systems work, because those have elements of proportional representation.