Items in League are a big dumb mess
League's item logic is one of the most convoluted systems I've ever encountered. Ranged carry champions fill their item slots entirely with swords, axes and cutlasses, and melee champions can build a "rapid fire cannon" and crossbows. But then ranged champs can't build tiamat items because... reasons.
Even better than the logic is the names. Because nothing says magic pen and grievous wounds like "Morrellonomicon". Oh and let's come up with a good name for a suit of armor that resists magic damage, I know, how about "Spirit Visage." "Spirit" because it sounds magic'y and "Visage"because visage means a person's face... oh wait... what have I done...
Luckily I'm here with something that resembles an answer. I've come up with a new item system that will make sense and be easy to understand even for the biggest idiots that play this stupid game, like me.
We divide all combat items into two categories: normal items and enchantments. Normal items are not built out of smaller components and must be made in one purchase. They only have flat stats (AD/AP, armor/mr) and an additional attribute: sockets.
A normal item gets more expensive the more stats and sockets it has. Normal items are further divided into bows and blades. Bow items can only be purchased by ranged champions and blade items only be melee champions. Have I lost you yet? Because I'm lost. I'm not joking. Please send help. My address is 176 Connoly... OH NO! NOT THE STRAWBERRY MARMOLADE AGAIN!!11 AHASNHOEANTSHOENTASHAAAAOE!NOAENATS111111111
Moving on, enchantments are all the special attributes items have (unique passives), like Static Shiv's "static" passive or warmog's out of combat healing. You buy enchantments to put in the sockets of your items. Some enchantments can only be socketed into certain kinds of items so read the description!
I have an example. You're having a rough laning phase, your support is some subhuman trash that should have never been born but they're your best friend since 7th grade irl so you just type 'lol' in chat as you hover over the exit game button like it's the 6th chamber in that game of russian roullette you always play when some life event occurs where you're forced to leave your house and you haven't shaved or cut your hair in 4 years so you become a real life bigfoot sighting in any place you appear, and can only manage to back with 850 gold. With this you can't afford a BF sword with even 1 socket (1300 gold) but you can buy a doran's blade with 4 sockets for that price, and so that's what you get. Your opponent backed with 1500 gold, and buys a BF sword with 2 sockets. Your opponent has better mid game damage but you do have the silver lining that you get an extra 2 sockets to fill with enchantments which could benefit you more late game. Meaningful options.
Now what do we get for this change, besides the fact I convinced you to read a giant post on a board filled with crazy people to temporarily distract you from your inevitable demise? All the unique passives can be neatly extracted from the items themselves. For instance, the 4 zeal items become 4 unique enchantments that can be socketed into any normal bow. The tiamat line would become 2 different enchantments (ravenous or titanic) that can only be socketed into a sword or axe.
Do you want to gamble for late-game dominance and hold out for a 6 socket BF sword at 2k gold? Or do you want to just get a 2 socket doran blade to get the 2 enchantments you're interested in as fast as possible? THe choice is yours you big dumb idiot!
Inventory complexity can be reigned in by limiting the very plausible concept that you can fight better with 5 swords. Have you ever tried to fight with 5 swords? I have. I juggled them 10 feet into the air offensively and ended up getting impaled in 3 places in my back and shoulder. I was rushed to the ER. When I came to the doctor asked me what I was doing juggling 5 large two-handed swords. I told him I wanted to be a League of Legends champion. Now I'm on a court-mandated cocktail of ambien, abilify and prescription pain medications. So much for my parole board hearing.
What if you could just choose 1 weapon, 1 hat, 1 gloves, 1 boots and stick a few ancient spirit demon things into them to get them to do what you want? Sort of like Darkins except more of them and purchaseable.