There's a sort by type setting which puts things into different blocks, so crafting mats get grouped together, as do meals and consumables, gear, etc.
Aye it's not perfect, there's room for UI improvements. I think the compromise people want is basically a display mod on the client side that makes it appear as though there are separate bags or compartments for different types of items, including the elusive fishing tackle box, without changing how things are stored and accessed as far as the servers are concerned.

Idk how feasible that is, but beneath the illusion of there being different boxes/bags it's still one big shared inventory so storing too many crafting mats means your tackle box can fit nothing. I think that's how it has to work for us to get those things, just a split inventory display option basically for the sake of finding things more easily.