Obviously the author of the article is completely clueless on many levels. Maybe they went by some conservative advice that 4% SWR wasn't good enough so 3% means 33x expenses, but then thinking expenses = salary is just wrong. For one obvious thing, your salary is reduced by taxes, OASDI, and Medicare. These things are reduced or non-existent in most middle class and middle-upper class retirements. The 33x probably also assumes covering big recurring things like mortgage and car loan that you shouldn't have in retirement (unless you are FI and have sufficient reserves to leverage these things through arbitrage, but now I'm talking advanced Mustachianism).
Healthcare, of course, is a wildcard, as is forward inflation. I'm not going to say they were right in the article, but things could be headed in a slightly more difficult direction than what we've experienced these last ~10 bull market, low inflation, ACA-introduced and supported years.... Shoot, things could get really difficult really quickly and could make this article look laughably generous if WWIII breaks out and America is deemed to be a bully and loses a war. Weimar Germany had a 0.5% SWR. Trump is certainly more along the lines of a polarizing Napoleon / Hitler (and prides himself on his Twitter and rally-speech prowess) than a status quo politician.
That's what makes the future interesting; you can never know. And typically, when you think you know, things work out so differently than you could've ever imagined (hence the 'plans are what you make while life happens' trope). That's why I enjoy FI but maybe not yet RE. Waiting for the world to work out the way you think it should is a fool's errand. And when retired people thank workers doing OMY, I'm glad to do it TBH. They are writing interesting things in the forum and on their blogs reminding me that I can be part of that group anytime I want.
All I hope, in life, is that I'm living my best life - and that I leave the world better off than how I found it.