What purpose do Proxy Advisers serve?

One of the large Proxy Advisers seems to be more than happy to sign off on the compensation of Credit Suisse CEO Thiam. And many institutional investors are similarly content with his pay. But where does that leave the ordinary investor - the great majority is not holding CS shares directly but invests their savings via intermediaries who are really fiduciaries. But how do they insure that their investor's best interests are represented? This is the great deficiency in all the discussions about corporate governance - the real participants have no voice!
(10-April-2019)