There is a cap on what income you pay in against. Its also adjusted with inflation. It makes sense because there is a cap on how much you can collect, but there is discussion of eliminating the cap (and not eliminating the pay out cap).The other piece of it is there's a SS cap. It's not outlandish, it's currently $168,600. There are likely many people who will draw the maximum, which again, is not earth shattering, I think it's in the $3,000s. Just googled it, $3,822.
Its also progressive. ie if you paid the max every year for 35 years, and I paid half the maximum for exactly the same time, my allocation would be much more than half of yours. ie its a type of social program - the less you pay the more you get comparatively.
Last and probably most important is SS is "on budget", meaning the federal gov collects the money, pays SS payments, and gives the excess to the SS trust fund. If there is a shortage the trust fund pays the government. The trust fund themselves figure they will be empty in a few years, at current estimates say they will be out by 2033 - at which time using current estimates they would have enough coming in to pay 79% of scheduled benefits. Of course planning on what will happen 9 years from now is a fools errand. https://www.ssa.gov/oact/trsum/