I think the point is that given the size of the error bars, that much precision is not an accurate representation of the confidence we should have in the result. 25.68% might be the observed change, but it's not one we should have much confidence of being accurate, not to four significant figures. Glibly put, it's false precision.

No-one I've seen arguing for fewer significant digits says that a probability of 0.999 should be rounded to 1. Nor do they say it's ok to round 0.5 to 0.