The problem with most of the examples you provided is that most are ranged/magic/summon weapons that do melee damage. I don't think this should be the goal of balancing the melee weapons. My sword shouldn't remain UP just because these "melee" weapons exist.
Path of Exile has the same problem, "Melee" spells are currently rather powerful, and on meta. However, most builds that use actual melee spells are at best workable up until a certain point, and almost all of them suffer immensely from either not having enough damage to kill in a time efficient manner or not having enough defenses and health to survive. Some people say Melee is fine, but in reality it's just the "Melee" spells/weapons that are fine, Melee, as in being able to hit things with swords and such, and go in and get up close isn't. It doesn't necessarily need to be through armor or bonuses to Melee damage, and that's probably exactly the wrong way to go about it, however, something does need to be done, as most of the useful later game "Melee" stuff is simply a set of no ammo/no mana ranged weapons. I feel that swords at all levels should be buffed, but I can't actually make that change.
I think that most people don't want Melee to be defined by these "Melee" items, especially not when throwing is so useless in the late game, I really think that quite a few of the no mana "Melee" weapons should be used to expand the throwing class, like Shadow Knives, or Vampire Knives, and both of these should be reworked to be more useful as consumable items rather than what they are now.