So I've got a bit of a selfish reason for making this post aside from starting an autistic debate about the back end of RPGs again. I'm just playing around right now with learning inventory mechanics and learning them.
Every time I look at grid inventories, yes they're sometimes quite nice visually laid out and everything and it lets you sort stuff well as the player when they're coded properly. At the same time though from the player's perspective I have never really cared much about grid vs list I played the hell out of Skyrim and Fallout 4 and I actually quite enjoy the list inventories because you can quickly scroll down clicky click your way through stuff and you're done whereas with grids you're dragging and dropping things constantly and having to split items in a fairly tedious way.
My main point with this ramble is though thinking about inventory design does anybody here actually care that much about what the inventory screen looks like if it's clean and usable? I bring this up because if I choose to code a list over a grid in my projects that have inventory systems it's a remarkable difference in the work load, lists are definitely easier to deal with and take less code compared to complicated grid systems if all you want to do is let people pick up and drop stuff or equip things and there's not much else going on.
For extreme examples, think Skyrim vs Diablo 2 in terms of how they have their inventories. Been fed up of bloated RPG after bloated RPG being released so I'm going to play around with these ideas for the lulz while I think about my other work now my RL garden stuff is calming down.
You forget that a game can have hover-over tooltip overlays, at least on PC (with mouse). Still, I agree that it's more ideal within smaller numerical ranges, though a proper weight/carrying capacity system can cover usually cover that almost on its own.
Also, some items don't really need a lot of extra details when it's plainly obvious what they are. IE, medkits and bandages, ammunition with icons that make it fairly clear what kind of ammunition it is, etc.
Hover over is also inferior to having the grid be on one side and the item details on the other.
Sort of depends on the situation and context I guess.
For me, if I'm diving in and out of the menu a lot I'd rather not fill up more screen space with an entire section just for item details that I may or may not need to check on a frequent basis.
I'd also rather not have to actively select each item in a grid (or list for that matter) to glance at the item details.
But that really does depend on the kind of game in question. For a strategy game with a lot of listed stats, I probably would prefer a dedicated section of UI for a unit's details.
Item comparison's another UI feature to consider as well, although I've rarely been a fan of how most games implement that.