My point was that the highly paid, these days are often only highly paid for a part of their working life. For example the people selling mortgages to unqualified people as fast as they could so they could rake in the sales commissions, and then have the loans bundled and sold off shore with neither they nor their companies having any skin in the game. Now that they are no longer employed or only can get much lower paid jobs, I’ll bet a lot of them wish that they had the income above $108,000 counted for their SS reserve. Others who have short or intermittent high level earnings periods might include sports figures, actors, authors, etc. We hear the sad stories of sports figures, for example, who have an injury early in their career and end up broke and poor in their old age.
To address your concern, there could be some sort of maximum life time limit, wherein after you had paid in enough to cover your payments at the top allowed level, then SS would no longer be taken from your income.
A better alternative to Social Security for those younger than 40 is the Chilean model. In Chile, you have the option of government run SS or you can opt to set up your own account in your own name which the government can not spend from, and you have choices of investments supervised by experienced investors.