Getting rid of the different materials gets rid of a form of progression that the Pit is intended to provide.
- Ingolith drops at 41, so until you reach T41, you cannot get past MW 4.
- Neathiron drops at 61, so until you reach T61, you cannot get past MW 8.
Seems entirely intentional, no? When you start out doing the Pit, you can’t just jump right to 41 or 61 (well, depending on class right now, I guess). You need to work your way up. This kind of game is all about some kind of progression, no? The 3 tiers of mats are a progression.
(I was kinda initially assuming the tiers were more spread out, with Ingolith at like 50 and Neathiron closer to 100, and we would be able to go notably deeper after MWing because the power boost would be a little more pronounced, kinda like how the game changes slightly after hitting 50 and you start unlocking Paragon. Alas, that was not the case.)
The only reason they convert down at a ratio of 3:1 is to make it more efficient to farm the higher tiers for mats if you want to redo lower MW. Having to farm T40 for Obducite, with it proving not even remotely challenging, would have been dumb.