Nothing stopped about this. Our demographics have changed for the worse in this regard, is all. From the latest report from the SSA's Board of Trustees:
"Social Security and Medicare both face long-term financing shortfalls under currently scheduled benefits and financing. Costs of both programs will grow faster than gross domestic product (GDP) through the mid-2030s primarily due to the rapid aging of the U.S. population. Medicare costs will continue to grow faster than GDP through the late 2070s due to projected increases in the volume and intensity of services provided."
Furthermore:
"For the sixth consecutive year, the Trustees are issuing a determination of projected excess general revenue Medicare funding, as is required by law whenever annual tax and premium revenues of the combined Medicare funds will be below 55 percent of projected combined annual outlays within the next 7 fiscal years. Under the law, two such consecutive determinations of projected excess general revenue constitute a “Medicare funding warning.” Under current law and the Trustees’ projections, such determinations and warnings will recur every year through the 75-year projection period."
It's a good read beyond the summary, too: