Item Randomness

I've seen this opinion expressed before so I know I'm not the only one, but I really, really do not understand riot's reasoning for making items as random as they are. I mean the items you get are already random, isn't that enough? Getting coins instead of items is annoying enough in the first three rounds, but it's even worse in the later creep rounds where you can get anywhere from like 1-4 items depending on your luck. It just confusing when I look at the title of the gamemode "Teamfight tactics". The whole point of the game, I thought, was to make the best team comp with the heroes and items you have been given. But when you've been given significantly fewer items than other players, that's not anything to do with tactics, just dumb luck or lack thereof.