Well, first of all, it just doesn't make sense that wearing 4 pairs of cargo pants will let me put a gallon jug of bleach in my pockets (Not 100% to scale, just an example.) With this system, the containers would have their own individual storage value, so you wouldn't be able to, I don't know, carry a tire in your hoodie + long sleeve shirt + whatever other low volume clothes stacked together. Also, it really isn't an oversimplification. It's just the addition of a change to how volume works, as well as a slight change to the inventory screen. And yes, the de-cluttering, organizing, and grouping is also a benefit of this system.
What I want to do is make the storage system make just a little bit more sense, as well as adding some level of convenience to the whole thing, while implementing it in a way that doesn't require constant micro-management from the player. To make it optional, in a way, we could just have a sort of priority system so that the game decides where the player puts things. If they want to, they can organize and what-not later, or just leave it be. It would only be absolutely necessary if the player had to reorganize something to make room for just one more item.
A few drawbacks I can see could be a rare case of not knowing whether you just don't have enough space for that item, or your inventory isn't organized enough. Another problem could be that this will make the inventory list be a little bit longer, especially for players who like to wear five backpacks, a rucksack and two tool belts. However, it would only be by a little bit, and if you have that much on, your inventory is probably pretty packed.
Unfortunately, I have no idea how to do any of the coding, and I highly doubt anyone would do this, or even pay attention to this. I mean, my accounts only a few weeks old. And I've made like 3 or 4 posts. So I doubt that anyone with the ability to change this (One of the devs) will see this.