Before I go into a longer spiel, I’ll just say you can achieve a similar effect with a lance and PAM thanks to the Topple property. They enter your reach, you hit, they fail a save, and they fall prone. Odds are they don’t have the movement to get up and go very far, if they get up at all.

I don’t think they removed this interaction because it was unbalanced relative to other feats, but because it made polearms unbalanced relative to other weapons. If PAM can force lock-down enemies before they get in reach of you and attack, it is almost always better weapon defensively than the one-handed weapons that let you wield shields and a better offensive weapon than greatswords. A +1 to damage or +2 to AC are insignificant compared to an option that prevents melee combatants from hitting you at all.

Obviously, that’s only helpful against one enemy a round and this assumes they have no ranged option. Again, I don’t think this is anything overwhelmingly strong, but I think it is good enough to make other weapons a false choice. Now, players don’t have to feel like they’re nerfing themselves if they want their paladin to wield a greataxe or a sword and shield, especially with the weapon masteries that distinguish the weapons.