I don't mind the idea of an encumbrance system where it makes sense. Like, the idea of being able to carry whatever you want into combat feels obviously wrong to me, since you can just overwhelm any challenge with endless inventory - like you just grinded an endless supply of healing potions and smart-bombs. Encumbrance caused by your combat-relevant inventory creates the idea of a "build" of your character, it creates interesting decisions about which combat gear you're going to keep available to roll with (or non-combat gear if your game's core loop isn't combat-driven).

Although I do see the argument that it shouldn't be coupled to a weapon-durability system. I like weapon-durability as a way to make players fully explore all of the gear available instead of just getting "The Good One" and then never ever switching and making the optimal strategy super boring (yes, Steph Sterling, I'm That Guy) but it means working on the "build" of your character is constant fiddling and decision fatigue.

Either way, all that falls apart when it's stuff you're only carrying for saleable loot or for crafting materials. Unless you have an interesting and fun gameplay mechanic to provide supply-lines, that's just adding tedium for the sake of realism. Yes, it's not realistic that you can carry unlimited bricks, but taking that away doesn't add anything interesting to the game, it just adds tedium.