tl;dr: Get rid of the 80 different ammo/reload perks and just compile them together. More general perks = less vault space taken up and more freedom to just focus on Fashion Souls.
I feel like this a somewhat minor topic so it doesn't get talked about as much, but I would really prefer if Bungie did away with the "10 different possible perks per armor" system. For those newer to the game, back in Y1:
Chest Armor gave you + and + while Raid Armor gave you +Special Weapon Ammo in general. You didn't have to choose one or the other, which was better since if you were running Armamentarium, you got both ammo perks, and now unless you're running an Exotic with +Special and +Heavy or you're using a Hand Cannon, you pretty much never use the extra primary ammo perk over the special weapon.
Raid boots in Y1 just gave a flat +Heavy Weapon Ammo bonus, which was really nice as it was essentially two extra rockets and a decent amount of extra machine gun ammo.
Helmets could roll increased melee speed so you could get both increased throw distance (Via gauntlets) and melee speed. Some complained that this was "too good" (Which no one ever did until Bungie changed it randomly), but all it did was cause some players to keep Y1 helmets with Switchblade to keep both perks anyway.
I would prefer a similar way of doing things in Destiny 2.
Have gauntlets roll with either Primary Reloader or Special Reloader rather than having 8 (Possibly more if Destiny 2 introduces new weapon types) different reload perks. Maybe give some Exotics or Raid Armor Heavy Reloader in addition to one of the other perks.
Go back to letting us have both ammo perks on chest armor, which can be any random primary and special. Raid chest pieces can have universal primary and special. At least one Exotic chest armor per class should have +Special and +Heavy. I really don't want a repeat of Y2/Y3 Destiny where Titan and Warlocks got multiple Exotics with both perks while Hunters got zero and the one that used to come with +Heavy (Lucky Raspberry) had that removed too.
I would just remove the "Decreased Arc/Void/Solar Burn damage" perk entirely and reduce burn damage taken in general. They did that to us with TTK. Why not make it general?
Now I'm sure some will say that this will "make things too easy" or "reduce the grind too much", but I honestly disagree. They can keep the current stat roll system where the Int/Dis/Strength roll is random and some will be great while others might be terrible, and there will still be some variation in perks options. People will still grind to get great stat roll armor pieces. This would also free up vault space for those trying to have an armor piece for every weapon type for PvP purposes.
Just give me more consistency so I can focus primarily on fashion rather than what perks this armor piece may or may not have. I loved the overall simplicity of armor in Y1 and would prefer we have a similar system in place for D2.