Cut it by a fith by filling every position tomorrow. But then by Monday more are made unemployed, more jobs positions are created. Its an equilibrium, not a simple x and y. Plus, as you put more skilled workers in unskilled jobs, there's more unskilled unemployed with no positions to move into. So you can't just pretend there are plenty of easy to fill jobs out there.
Too many in one house will cost the NHS more, pushing up what is already a huge budget.
That number is fairly consistent. So no there's no need for it to be that high. Of course jobs are lost and created. But there's shouldn't be hundreads of thousands of jobs constantly.