If you want to remain a renter your whole life, staying home eating a very sparse diet, and forgetting about any social life including eating out, movies, other forms of entertainment, then sure you can survive for under $100K easily.
You won’t retire on much more than SS. You will more than likely have to access Medicaid, because you can’t afford straight Medicare without one of the various plans out there.
As for doing much in your golden years, you’ll be able to play board games if your spouse is still around, having lived that kind of life with you.
Wow - reading this thread makes me glad we live in a poor rural area of SW OR, paid cash for 5 acres years ago and built our own house (such as it is) and owe nothing... or we’d be in a trailer at some trailer park.