I could be oversimplifying, but I don’t think it really matters where social security is at at any given moment. The government can choose to fund it, defund it, privatize it, neglect it, etc. as they like. The fact that it currently exists and has funding is no guarantee that it will continue to exist, and the fact that it’s on course to start diminishing is no guarantee that it’ll continue to diminish.
It’s a policy choice, is what I’m saying. It may very well get reduced or eliminated at some point, but it’ll be because of deliberate decisions made by the government, not because the big pot of money ran out (although they may use that as an excuse).