The reason you don’t pay into it over a certain income is that it was started as a suppliment to your retirement and a safe guard for those that did not save for retirement (as opposed to a huge wealth distribution). The benefits are capped so you will not collect anymore in benefits even if you paid so much more in. So how can confiscating another 6.2% out of higher income workers be “fair”?
As a sole prop, I already pay twice. So now, old blue wants me to pay three times. Maroon.