The cause for the shortfall isn't the expense that Social Security is supposed to cover, which is to provide enough income so that Seniors who've paid in are guaranteed enough income so that they can live their senior years without ending up dying in the streets from poverty.
It's always had problems. When workers in the worst jobs died before they collected, the money ended up subsidizing "rich old ladies with blue hair and funny drinks with umbrellas in Miami". It became a survival of the fittest transfer of wealth.
Then, all the other stuff got added to it and the payments are much more than just providing a base life just-above-poverty level of income. Then there's the cutoff where high-income people don't pay intro Social Security after they reach an income cutoff.
Another problem is that many people who are spending less of their work years paying in because of job instability.
What's my point? Social Security could be fixed if (1) the economy is fixed and (2) it goes back to being what it was supposed to be, a safety net to stop the elderly from dying in the streets.