What is projected to happen in 2034 is that Social Security will run out of its excess reserves with the result being that retirees will only get about 77% of their current amount (about a 25% decrease).
The above is worse case scenario.
Of course, no politicians will allow themselves to be holding the bag should that scenario play out so you just know they will come up with something "miraculous" between now and then. Most likely during the 2032 campaign season.
Never happen. They will just keep making fiat money.