Why is this specific mechanic during Relics Quests still that way?

[dspguy]

I'm talking about the turn in if you want to advance a step.
Currently you need to be the Job for the Weapon you want to power up, but you cannot equip the weapon, which forces you to aquire some weapon just for the 2 seconds you need to turn in the quest which is extremely annoying.

The quest text logs which class you were and which weapon you want to turn in, so why are you still forced to be that class on top of it?

Think about every turn-in you've ever done. The reward goes into your inventory. If the weapon is in your main-hand and you turn it in, what job are you afterwards? You have no weapon. No job. That isn't a "state" that FFXIV knows how to handle. Should it be possible? Sure. I wouldn't be surprised if they are wary about making changes to code that has been in place since at least 2013, if not carry over from 1.0.