ALL pensions, except the government statutory Old Age Pension, and Civil Service pensions, which are paid out of current tax take. Are invested by the pension funds, in the city. In government bonds, and stocks and shares.
IF the activities of these investors, and bankers is curtailed, and their remuneration limited by statute, they will not have the incentive to try harder. Then the already reduced profits that they produce for private pensions, will fall even further.
Even pensioners pay tax, and help fund the pensions paid from general taxation. So in effect, the more they earn, the more tax is paid, both by the investors, and the pensioners.
In short, they are a necessary evil.