I kind of like the limited inventory in some games as it’s more ‘realistic’ - in the context of teleporting, magic and monsters being relalistic, and I think it adds a degree of decision as to what you carry with you, which can be a great thing.
But in some of the games you mention limited inventory is really counterproductive. In PoE there are so many items being dropped that limited inventory feels like a curse, particularly for new players that have no idea what to pickup or use. It only begins to feel about right once you are into Cruel/Act 6 and your loot filter is kicking in to not show 99% of the loot that enemies drop. You’re also doubly penalised by having to spend currency (portal scrolls) to travel anywhere to sell them.
Personally I’d like to see a weight based inventory system in a game like this. Rather than have item’s take up space they instead have a base weight. So starting out you might be able to carry only 3 full suits of armour or 20 pieces of jewelry equivalent. So there’s no real item slot limit other than how many tabs you need to carry all of that stuff. Character progression through base stat or passives could allow for greater encumbrance, and bags themselves could be a nice piece of game loot that could improve you ability to carry gear - either through a greater weight allowance or multiplier, or have a % weight reduction on certain item types. A similar feature could be part of belts in the game, eg. Heavy belt equivalents could allow for greater carrying, much like weightlifters/strongmen make use of them.
It would be important to have a system like this be very intuitive so that your’re not replacing inventory tetris with inventory math. Perhaps items have a 1-10 integer weight scale (where a stack of consumables might in total only be 1) and then allow as many slots as the player wants to have. I have no issue with Quest items taking up weight but make it realistic; if we’re being sent out to collect a black raven feather it shouldn’t weigh as much as as a broadsword. Likewise it shouldn’t be surprising if the 4 Tomes of Nmerand we were asked to locate are a bit of a pain in the ass to lug back to the village.
What they shouldn’t do however is tie inventory size and weight together as a limit (and they definitely shouldn’t then make increasing weight and space a cash-shop purchasable thing. I’m looking at you BlackDesert, for how not to handle inventory management)
edit: weird. the forum ate my homework last edit