The sorting function is not really useful given the inventory size. Instead of sorting by item type and then by item power, just sort by item power. This is more useful for an inventory of 20-30 items. Better yet, make a “default” sorting optionality.
More importantly, a filtering function would be so desirable. I want to see if any items in my inventory have certain stats or criteria. I want to know this fast, so i can go to the next dungeon. Reading 30 items worth of stats is tiresome and a huge drag on the game. If I could know at the click of a button whether any items were worth looking at further, that would be a huge QOL improvement.