Why were balkline billiards rules created?

Balkline billiards rules were created to prevent expert players from scoring indefinitely by maneuvering the balls into a corner and repeatedly executing simple, soft shots.1

By drawing lines parallel to the cushions, the table is divided into areas known as balks. When both object balls are within one of these areas, the rules restrict the number of caroms a player can score before they must drive at least one ball out of that space. To further prevent players from circumventing these restrictions by positioning balls near the intersection of a balkline and a cushion, additional squares called "anchors" were introduced, which are treated as separate, restricted balks.1