Unit design or inventory management in games

I’ve been playing a lot of tactical RPGs lately - Bard’s Tale IV, Operencia, and now Tower of Time. While there are certain aspects I’ve liked a bunch, they each have had something that bothers me. From a mechanics standpoint, I think I like Tower of Time the best but it I started falling into the same place as the others - I just started losing the will to play.

The light bulb went on and I finally put my finger on it. I find dealing with different damage types very tedious because if makes me focus on the part of the game I find the most annoying - inventory management.

I was having trouble with a battle and came to the realization that I thought it was because of the poison attacks from the enemy. To deal with it I could see if I have some armor that boosts resistances, or maybe change the enchantments I have on my armor. I find that type of stuff tedious.

I don’t like it in Dark Souls when I need to try and guess what damage type I should be trying to do or protect myself from. I don’t like when in tactical RPGs the difficulty comes from just doing the wrong type of damage or not protecting myself from the right type of damage. There other ways to make it more interesting - positioning, or when to commit to using a resource or power, etc…

It’s related to unit customization with a game like Gal Civ and needing to change the balance of lasers / missiles / armor / shields, etc… It is usually just tedious busywork. It isn’t nearly as bad when unit customization isn’t allowed and we’re just dealing with inherent unit abilities (spearman vs cavalry) because the player doesn’t need to be constantly updating unit design or changing loadout in a RPG.

Why is this mechanic so common? Do most people like juggling loadouts or updating unit design?