S&P500 lifetime inflation-adjusted return is 7-8%. meaning, if one put away 150K in the S&P500 at age 20 and worked for 40 years, putting away nothing else but gaining that inflation-adjusted 7-8 (conservatively call it 7), and then pulled out a measly 4%, allowing the remaining growth to account for inflation, they’d be pulling an inflation-adjusted income of >80K, ignoring any other income.

I’m not saying one shouldn’t put anything else away or strictly count on matching historical S&P return, but yes, putting away 150K at 20 could absolutely mean you don’t need to put anything away again.