Let me walk you through one of the many times I've had troubles with finding items for my retainer to gather, or to craft something on my own.

""I need my lv.60 miner retainer to get me some Iron Ore. Is it within lv.1-5 ventures? Lv. 5-10? Lv 10-15?

Hmm I need to get some yew lumber. What level range was it in again? 10-15? 15-20?""

You can imagine here there are multiple times I'm having to click around just to find an item that I'm looking for.

So what's the major problem?

It's that intuitively grouping items within level ranges doesn't make any sense.

If I asked you what level would a Snurble Tuft be it's hard to really define exactly what level it is. Then why are items grouped up in levels then?