Dacron was once the primary line for fishing before the discovery of Nylon. Nylon proved to be so superior to braided Dacron which had poor knot strength, low abrasion resistance, and little stretch, that Dacron almost disappeared from the market. Today it is used primarily as a backing material on fly fishing reels.

Normal braid is far more superior in knot strength, abrasian resistance and friction, allowing it to cast much further. Not to mention, the diameter of braid vs dacron is far less, allowing you to put more of it on a spool on a distance per lbs ratio.