Your cedar fence is still beautiful at year 20
Most Shawnee cedar fences leaning or graying out by year 8 didn't fail because the wood gave up — they failed because the posts were too shallow and nobody put a fresh stain coat on. Ours go 36 inches deep in wet-poured concrete and the first stain coat goes on at 30 days. We log the date and call when the 2-year re-coat comes due.