I kinda like it, but what the market is doing right now definitely has a real impact on even smart, conservative investors. The FIREcalc site does a good job of explaining this. If you take the same assumptions of nest egg + spending, you can end up with wildly different results by changing just the year you retire in.
It’s another great reason to try to budget retiring early if you can, so that you’re still in prime working shape to put in a couple more years if the market ends up sucking right when you were gonna coast.