It seems people go through phases regarding the 4% rule.
Phase One: Just learned of the possibility of FIRE and are "on board". Did some compounding interest math & Cfiresim, 4% rule seems legit. Plus all these internet people are saying its cool, so how can it be wrong? Unknown, Unknowns.
Phase Two: Middle to late accumulation and has been more exposed to the details of investing/cashflow, ect. Now sees the risk in a straight 4% rule, but not too concerned. Draw-down is down the road, plus even part time work seems better than what she's doing now. Known, Unknowns, but not immediately concerning.
Phase Three: End accumulation/beginning draw-down. Small chances of 4% rule failure are exaggerated. Whatever the financial markets look like, the future is obviously going to be worse than historical. After years of planning the idea of failure is scary. The idea of working again for less $ at some unknown point also sucks. These are the folks most concerned about the 4% rule. Known, Unknowns with potential immediate consequences
Phase Four: FIRE'd for multiple years. Returns have been good and FIRE'ee accidentally made a few unplanned thousand dollars each year due to serendipitous opportunities which arise from freedom of time and location. WR is now well below 4%, so no concerns. OR Horrible recession, stache dips to levels that are scary. FIRE'ee decides to take some part time work to avoid long term failure, even though the numbers are still on her side; "better safe than sorry". FIRE'ee manufactures some employment around life, whereas before life revolved around employment. Soon recession is over, WR back to under 4% and FIRE'ee thinks "wow, that wasn't so bad, I can't believe I wasted so much time worrying about the worse cases of the 4% rule"(this is where MMM writes that article). Either way it's now Known, Knowns.
I'm sitting squarely in the phase two camp, trying to learn from the phase four folks so I can partially avoid phase three.