Very few ministers are actually qualified to do their job, they learn on the job on the whole. The point about being elected is that we, the public, get the chance to remove them. That is pretty important imo.I am in two minds about that, because just being elected an MP doesn’t necessarily qualify anyone to be on the cabinet either.
This is where in principle (and if the current guy wouldn’t abuse it) like the US system. The president nominated someone qualified who then is ratified by elected people.
Don't forget they will not be quizzed in the House by MPs, they are not allowed in the HoC. That makes them even less open to scrutiny. Have them as advisers, not as top dog.