It won't rot off at the ground line — that's why the cedar's out
Olathe's dense, slow-draining clay holds water against a cedar post butt, and ground-line rot is the single reason most 20-year fences here finally come down. Vinyl doesn't wick moisture and doesn't rot; the post rides on a steel-sleeved concrete footing that the clay can't feed on. The fence you're replacing tells you exactly why this matters.