While true, PL also generated more rings, necks, and cloaks while making it harder for players with unique weapon types to get those pieces. The loot wasting of items nobody can use in GL were offset by loot that nobody needed after a few weeks in PL. There are too many variables to determine which would be more likely in a vacuum, but both systems had ways for non-useful loot to be generated.
But what PL had no protection for which GL does is with making it more likely for players who lack items from the raid to get the items. My druid here got his heroic tier chest from the vault this week. Since I won’t be running mythic raid, I will have exactly 0% chance to roll need on a tier chest token the rest of the season. If I find myself in a PUG that kills Broodtwister, every mage, hunter, and druid has a higher chance at getting the tier chest. Whereas with PL, I would have the same chance as all of them to be given the tier chest token the rest of the season.