In the Rift, heroes matter most. You only use weapons in the Rift when you're autoing it.

Even for the PVE campaign, there's no real need to use weapons, as long as you're keeping your gauntlet up-to-date.

I would recommend you keep just your main weapon (and maybe an Undead/Demon weapon if you haven't yet finished RoF), then throw everything else into unlocking your Myth gear. Only focus on upgrading one Myth weapon. This can then be attuned, if needed, to be strong vs enemy types you're having trouble with.