The article says it depends on your lifestyle how much you need but then arbitrarily assigns after-tax numbers way higher than what the median/average retiree spends. I mean, have high numbers, sure - but why not then run the gamut and have say, 20k, 30k, 40k, 50k in addition? 2017 U.S. annual household spending for those under 55 averages 57k, for 55-64 is 59k, for 65-74 is 46k, and for 75+ is 38k. Not everyone has a household of 2 while in retirement but I think those lower after tax numbers would be better to use and cover many more situations. If you plan on spending 100k per person in retirement, I don't think taking time reading what businessinsider has to say makes the most sense because you've got to make that tee time with your financial advisor who should be pulling up in the 60k car you helped purchase any moment.
I have a hard time imagining how the hell my wife and I would spend 130k (of post tax 2019 dollars) even if we tried to, let alone 200k, and we are by no means all that Mustachian.
Also, this is picking nits but I thought the adjective 'conservative' was annoying when assuming 3% for inflation. It hasn't been higher than 3% since 2007. Was this article written in 1989 rather than 2019 by chance? I'm fine with using 3% as an assumption but I would think that would be on the aggressive side given recent history (I don't think our government wants flirting with double digit inflation to really exist again if it can be helped) and is more of a worse-than-average scenario.