Unless they made Golden Pinaps rare as shit I think they would be too game-breaking outside of legendary encounters, where they may not even get used.
Golden Razz were introduced basically for legendaries with low catch rates. For 10 balls, attempting to catch a Rayquaza with a regular Razz and every other bonus applied only gives each ball a 9% success rate, topping out at 62% for the encounter if every throw is a curved excellent. GRB ups this to 15% per ball and 81% overall. With rare candy being fairly easy to get from higher-tiered raids it's a safer bet to take the 3 freebies for catching it than to risk getting no candies from a Pinap or Golden Pinap attempt.