The basic problem is that there are only so many possible uses.
- Gating content behind an eridium cost (e.g. arenas/raids)
- Loot sources to which you can pay eridium to improve the loot they drop
- item crafting (my idea: pay eridium to add or change an anointment)
The problem historically is that gearbox can’t seem to balance the eridium cost against the resultant loot so that the cost is non-trivial and players actually find it worthwhile to use the eridium (e.g. Tina DLC dice chests).
I for one would really like to see a crafting feature. And with some degree of care in the design, such a feature could be useful to players without being game-breaking.
I hoped at one point that the grinder in TPS was a signal they were moving towards weapon crafting of some kind in future games. But having not heard a peep about it from the devs I’m now inclined to suspect that it’s not happening.