Not how it works. Social security is a pay as you go system. You are taxed, that money goes straight to those eligible for the program. There is a trust that was created in the 70s/80s to deal with the extra receipts SSI got from there being way more baby boomers than retirees. Now it's the opposite there aren't enough workers for all the retirees. So now the trust is currently paying for the boomers and will run out in the early 2030s. When this happens, retirees will only be subsidized by receipts from direct payroll taxes. Benefits will be reduced, but not go away entirely. Once the boomers die, there will be a huge burden relieved from the system. And then when the millennials (which as a cohort, is an echo-boom, larger than the generations around them) gets old, they will probably vote in massive social security and medicare benefits just like how the boomers keep perpetuating the system that supports them in spite of everyone younger than them.
Removing the income cap is probably the easiest solution long term, though.