Ultimately the answer is that’s just the way the law and the regulations read. Altering the laws about SS are politically very fraught. And as well with so many sets of competing “facts” out there, there’s lots of room for citizens to become outraged at their legislators over what’s actually beneficial to them, if only they had the real facts, not the fake facts.
Here’s another factor:
The punchline being that SS was never designed to offer a high and safe ROI by waiting. The real ROI was supposed to be zero; where you were actuarially expected to receive the same amount of inflation corrected time-valued dollars whether you claimed at 62, 64, 66, or 70. The concept was that both the claimant and the government would be indifferent to the choice.
But then inflation and interest rates changed and the rules didn’t. So now waiting is a pretty darn good investment and a one-way bet for anyone who’s in decent health and not broke nearing age 62. Much to the government’s chagrin. Encouraging more waiting at the current high ROI is almost certainly a money loser for the government.
As between keeping the status quo or allowing more waiting past 70 while also trimming (read as “gutting”) the ROI, I’ll stick with status quo thankyouverymuch.
Minor aside: I’m not sure where you got “70-1/2” from. AIUI the SSA limit is starting to claim in the calendar year you turn 70. Which means anywhere between just barely 70 on 12/31 or almost 71 having turned 70 back on 01/01.
“70-1/2” used to be the latest date to commence RMDs from IRAs. Is that what you were thinking of?