The usual nonsense - the Left tries to pass this off as true because they want to avoid any meaningful reform of a broken system.
Reform might actually start a conversation about its scope and necessity - and the Left must plant their collective head in the sand in order to preserve the status quo.
At a minimum, SS was never meant to be a full-blown retirement pension program. The original age of eligibility was also the average age of mortality - SS was designed to be a supplement, not a 20-30 year standalone pension plan.
That said, I don't think outright privatization is politically feasible. However, I do believe in setting up an alternative system that you can opt into that essentially mirrors some of the benefits of a private fund/annuity (I think CATO had a plan like this in a paper) - give retirees a choice.
And the alternative can be run like a generational mutual fund that gets more conservative as you get older (and it would already be fairly conservative to begin with).
But I do think a feasible alternative that incorporates some level of privatization must be part of a government program or oversight - Americans, for better or worse, have generational expectations of SS being there, and I doubt there would be much chance of making that disappear.