a year's worth phone service on Tracfone is $130

Amen! I do the same...

But otherwise...I'm single, retired, age 65, my condo (a lower end one at that) is paid off, car is paid off, and other than doing some traveling I live quite simply. My main activities are walking the dog and beach volleyball, neither of which costs a dime. I live in southern California--high cost of living--but I don't ever run heat or A/C in my home. My gas and electric bills are minimal. And last year I spent...nearly $90K, even while getting hefty ACA health insurance subsidies. $10K of that was travel, $8K was property taxes, $10K was income taxes, $1K FICA (I did work a little), $5K charitable contributions, $3500 to get an estate plan, $5K doing some home renovations.

But even if you back out those "frills" (income tax is required, but I could have used my Roth to manipulate taxable income even more than I already did to get the ACA subsidies, and property tax is obviously required but I'm in a high tax region), I spent in the neighborhood of $45-50K. I eat out some, though not at high end establishments, and I like to eat good quality food so I pay more for groceries (yes, I use that word!). I don't buy expensive clothes (can you say "Costco"?). I pay too much for cable TV, but that's still just $200/month, and this year I'm looking to lower that.

To get to $20K/year? Wow, that would take a lot! Not having sales tax would help (where I live it's 9%), but I'd really have to scale back and focus more than I want to on pinching pennies. If the stock market tanks, I may need to do that, but otherwise I'll keep doing what I do.

I'd be surprised if I pay more than $200/month for food

If you're not tracking it, then yes, I suspect you would indeed be surprised at how much you are spending on food