That was me. I said that I thought every weapon (or weapon group) should have at least one property, and that the three damage types (slashing, piercing, bludgeoning) should have a meaningful reason for being in the game. But that in no way needs to add "complexity"... seeing as how the mechanics for all these things are already in the game, and have been in previous editions of the game.
We already have the place where weapon damage type comes into play. In the Skeleton entry in the Bestiary. Skeletons have a Vulnerability to bludgeoning weapons. But that's like the only one as far as I know that uses the Resistance/Vulnerability mechanic for weapon damage type (unless some monsters that were created in some of the adventures have it too but I didn't go through every single adventure bestiary.) Monsters up the wazoo have Resistance and Vulnerabilities and Immunities to "energy types" and "magic types"-- poison, fire, charm, sleep, thunder etc. etc... but why not more to the weapon damage types? Make selecting a weapon from one of these types actually meaningful. Make actually having them DEFINED in the game meaningful. Would it kill the game to have a dozen monsters or so have select weapon damage types affect it more or less? To actually give those terms meaning? Because right now, there is practically no point to those terms being there in the game. Skeletons and the 15th level 'Devastating Critical' ability of the Path of the Warrior sub-class. Whoopty-do! So glad we're keeping track of the weapon damage types!
Then beyond that... each weapon or weapon group gets a property. To me, that's a no-brainer. Because when a Flail is 1d8 bludgeoning damage and the Warhammer is 1d8 bludgeoning damage *and* Versatile... why would anyone ever select the Flail (other than purely aesthetic reasons?) Now someone might claim you can save 5 gold pieces by buying the flail rather than the warhammer... but come on. When you get 175 gold to start with to buy equipment... that reason is absolutely stupid. And there are a number of easy-to-remember properties out there that could be assigned that would not add any amount of "complexity" over what you already need to remember for "Reach" or "Versatile" or "Thrown" or "Finesse". Like Brutal (on a damage roll, re-roll any 1), or High Crit (on a crit, roll an extra damage die). Give the remaining weapons something to call their own.