Does the political branch make the decisions? No. But they choose the people that do!This by no means implies any control over interest rates. At all.
People are appointed, and that's where political input ends. And those appointed stay appointed, are not chosen lightly, markets do not react well to poor choice.
By your metric, you'd think our Supreme court judges were puppets too. They aren't.
People may have political leanings, but understand, that is not the same as allowing input where it is not allowed.
The government cannot interfere with the judicial branch, nor with fiscal policy. To do so, renders it a banana republic, or dictatorship, any attempts would be disaster, for those appointed take this very seriously.
A core part of the job is to ignore ministers, the PMO, and so on.
It is entirely independent.