"RPG Fans: What is the point of inventory?"
I think RPG's have been taking a lot of shortcuts on inventory for a long time.
You're carrying around your broadsword, spear, crossbow, and axe among other things, maybe an alternate armor set - and yet they don't show up graphically, it's not explained how you lug all that around the countryside, and you're quickly ready to go in battle with a monster.
It's pretty nonsensical and we excuse it as 'helping with gameplay to ignore it.'
Even things like eating and sleeping. I remember a game like Might and Magic I would deal more with this - you have to find food and eat it. I don't remember for sure but there might have been a chance of bad food as well, which would cause a problem. I think you had to sleep - and might get attacked.
Things that RPG's since have mostly said 'don't worry about that stuff, it gets in the way of gameplay'.
Some games have gotten rid of things like food, others have evolved it such as to a tradeskill.
One of the more fun uses was having alcohol give your character both some bonuses and penalties, the penalties a bit worse.
What's not as good is when inventory is made into a game limit that gets in the way of fun - and even worse when DLC is sold as the solution (hello, Dragon's Age).
(It's hardly alone - Diablo II's expansion added inventory, a premium subscription to the forgotten Dungeon Runner added inventory space, etc.)
Of course the basic inventory is fine in RPG's - which include 'loot' as part of the game in pretty much all of them, going back to the original Rogue and D&D.
The main feature around it is ease of use - some games (hello, Diablo) have included a lot of having to manually rearrange items to use every last square.