Public esteem, financial reward and historical acknowledgement are among them. Everyone can come to their own opinion about an individual's worth and can change their mind. All such rewards can be lost. But titles are forever. They contribute to the stratification of our society, discouraging a healthy belief that we are all socially equal.
Many honours are rewards to supporters of the government.
Recently Richard Branson, the founder of the Virgin business group, reported that it had been hinted to him that he could have an honour in return for a donation to the Conservative Party. It is particularly outrageous that a seat in the legislature can be had in return for financial help to a political party. A second chamber can be useful in that way. But it is better to have a democratic second chamber that can act with legitimacy and democratic authority. The monarch unites the country in a way that an elected head of state would not.