Social Security will not run out. It simply won't be taxing current workers enough to pay current retirees. This demographic problem was easily foreseen which is why there is a trust fund to "run out" to begin with. For quite some time social security operated in a surplus since there were many workers per retiree collecting benefits. Now we are around 3:1 workers:retirees and expected to drop to something like 2.2:1.

Where this gets confusing is that most folks seem to have the mental model that Social Security is a pension or some weird retirement account. It is not.

Social Security is simply a pay as you go means tested welfare program. It just means tests in a strange way. If you ended social security taxes today, the trust would run out in a few months and there would be $0 to pay retirees. It's current workers paying for current retirees. Social Security is simply an income tax like any other, but it's separated and marketed the way it is to purposefully make people think it's "their money" and make repealing it politically impossible.

It's just a means tested entitlement program funded by current tax receipts dressed up in fancy marketing. It functions much more similarly to SNAP (food aid) than it does a pension.