You have to change the way you approach the way you build decks. Instead of running Item heavy list, look for other ways of doing the same thing. Maybe you don't need a turn one Professor Sycamore of Lillie and can just play a Pokemon Fan Club or similar card. Maybe cut a Ultra Ball or two and run a Supporter. Do you need to play Max Elixir and Trainers' Mail? You might be able to cut these for more ways to find Pokemon or just add more Supporters. Do you really need four VS Seeker? Maybe try cutting one for some more Pokemon.
The goal is to look at your deck and see what needs to be there and what can do that card's job better. You'd be surprised to find out what cards work better. You just need to figure out what works to maintain speed and fight effectively against Garbodor.
So every other deck has to cut on items except garb decks then?