Barring some very recent personal catastrophe -- It's not like somebody just instantaneously arrives at the age of 70 with zero retirement savings. Folks in that situation have known for the greater part of a century whether or not they had a pension, and have been advised to save for retirement all along. If they choose to consume 100% (or more) of their earnings throughout an entire career, there should be no surprise that there's nothing for them except for SS. For those who had been working at extremely low income levels, their social security checks will be very close to what their income was anyway (due to the highly progressive nature of SS bend points.) For those who earned more than that -- it was their choice to over-consume throughout their life.
I'm all for a safety net... but sometimes you have to call out a lack of personal responsibility too.