Boy, you are getting stuff wrong.
Think about the different circumstances when it was set up from 50 years later. What changed? You're the one with math issues not to get the changes.
The people who set it up did just fine for decades (proving the Republicans who said it would not last at all wrong).
Yes, after decades, the changing demographics required adjustment. Unfortunately, the American people had given that task to the worst people on the planet, short of Joe "Crazy Guy Who Eats Wallpaper Paste" Rodriguez in Grenada, Ronald Reagan and Alan Greenspan, who came up with a way to use the issue to raise huge amounts of money - while then throwing that money away by letting the government borrow and spend it off the books.
The program itself - the most successful in history, perhaps, reversing elder poverty from 90% to 10%, very popular - which is why Republicans want it gone.
What Reagan and Greenspan did, what Congress and Presidents borrow, are not the fault of Social Security, they're the fault of the politicians and the voters.
Social security itself can continue as a great retirement program indefinitely, with some adjustments for the changing demographics.
We don't need 'reform' from a group of people - Republicans - who have the motive to destroy it to deny Democrats any political benefit, and shift wealth to the top.
the math that the people who set it up didn't figure out is compound interest. you know, the most powerful force in the universe. they also didn't figure out COLA or that there would be declining number of contributors to retirees (a problem with all pay as you go pensions). in fact, there is basically no math in the 1935 act, so they had to start fixing it in 1950 (hardly decades and certainly not 50 years later).
social security's tax rate has been adjusted upward continually since the program's inception. so, if decades mean 'after 15 years and then continuously afterward.' why? because the number of workers per retiree has always been falling. they probably figured that would happen back in 1935 but who knows. though there was no math at all in the 1935 law so maybe not. so in 1950 there was a 77% COLA, a 20% increase in the wage ceiling and 50% increase in the tax rate. there were a total of 16 increases in the tax rate before 1983.
again, there was no math, so that's pretty strong evidence in favor of my assertion that it was set up by people who don't understand math.
so, the rate has been adjusted upward. often. that didn't change in 1983. the amount of income subject to social security has continually been increased upward. that didn't change in 1983. the program has to buy government bonds. that didn't change in 1983. the government used a unified budget.* that didn't change in 1983.
looking at it the only thing that really changed is that automatic COLAs have been lower since then, but unless there's been some change in how CPI-W is tabulated that's just due to stagflation's end at the same time. 1984 is the only year in which the wage measure would have served as the basis for COLA but i don't see anything that says it was used. the one thing that changed legally is that a portion of social security benefits became taxable.
anyway, if you'd have read my post you'd see that either of my proposals would have prevented the government from stealing the trust fund, republicans and democrats.
*side note: raygun actually proposed taking it out of the unified budget, which makes deficits appear larger compared to unified budget, but not until well after he'd left office. johnson invented the unified budget because squabbling over which budget measure was to be used consumed a lot of congress's time. since 1990 it has been off budget.