This sort of analysis is common in the financial "advice" (sales, really) industry, but makes no sense. You shouldn't start from your income while working, but from your expected expenses. For example my 3 person household has about 40k/yr in expenses, which is more-or-less independent of my income, given that I make more than that. Once our mortgage is paid off, that will be more like 28k. The average social security benefit is ~18.5k/yr, so that leaves a 10k/yr shortfall at our current lifestyle, which only requires 250k in retirement savings at the 4% rate you're using. Our discretionary spending has inflated somewhat in the past couple years (some of it has been "buy-it-for-life" stuff like furniture), but my wife and I as a 2 person household could comfortably live on just SS once the house is paid off. We'd just be living like we did in our 20s again, and we were perfectly comfortable then. We'd also still have the things we've bought over the years, so really we'd be more comfortable. Presumably there will be some additional health expenses as we age, but as far as I know Medicare isn't so bad that we'd need anywhere close to $80k income in retirement. That additional $10k/yr lifestyle above SS could also be covered by $100/month contributed over 40 years at 7% real returns.

So assuming you can put together a down payment (possibly 3.5% for FHA loans), and assuming you believe in the long term stability of US economic conditions in general, the boring, responsible path to a quiet, comfortable life continues to work even below median income levels.

(This also assumes good health for most of your life. Certainly many people get the short end of the stick there, but many more simply don't take care of themselves.)