The right to trial by jury in criminal cases stands as one of the most effective checks against the tyranny of government. It is, as Winston Churchill put it, the ‘supreme protection invented by the British people for ordinary individuals against the state’.
If ID cards become mandatory we will lose much of our remaining liberty. Only law-abiding citizens lose out.
Since resources can’t possibly pull up everyone, but still might pull up anyone, the ‘rules’ can be tantamount to a mechanism for arbitrary arrest.
The problem with simply increasing police numbers is that it assumes a purely state-down approach, disconnects police function from their source of authority (the individual), and can become easily politicised and directed away from the real job of tackling actual rights violations such as violent crime and theft.