Politicians should be generalists not specialists. What they should do is surround themselves with experts is specific fields, and consider the advice they give.
Unfortunately, in many nations the politicians more frequently listen to the distorted scare and panic the media has created that week and base their policies on that instead.
The problem here is that it's all too easy to pay off experts to give advice that isn't necessarily "correct" but is what a special interest wants for some reason.
Further many of these experts are also allowed to remain anonymous (or effectively so) which means that they aren't even selling their reputation on a one-time transactions where afterwards they will be publicly humiliated or shamed. They are allowed to do this over and over.
I agree with your statement in principle 100% but in practice I'm not sure it's terribly effective.