CreamCloud0
Hero
the point isn't the specific types of elemental damage being done or that it's being paired with weapon damage, but the fact the elemental magic is supplementing the effectiveness of the attack with extra effects, in the same way spells like zephyr strike and lightning arrow work, granting you additional opportunity-attack-immune movement from the power of wind, or lightning surging out from the arget to strike everyone around them.Big problem there. 5e got rid of monsters commonly having elemental/physical resist and vulnerability in a way that was meaningful to damage type choices. All you need now is "not nonmagical bludgeon piercing or slashing"
being able to do things like:
repeating the damage they took from the weapon at the start of the foe's turn from the fire ingniting them
summoning a tidal wave cone of water to push foes away after you strike them
acid from your blow eating away at their defenses to reduce their AC
freezing the ground around the target you hit to surround them with difficult terrain