[Celjabba]

I think some of the primary factors for "Why Magic items" are :

-because players are human and enjoy getting shinny things
-because it boost performance on top of character growth
-because it allow a sense of differentiation, of personalizing the characters
-because it is seen as an achievement and/or something you can show off
-because it is a symbol of victory, a memory
-because 'free' loot is perceived as 'cheaper' than abilities purchased with xp, and therefore 'better' at beating the system

If you want to enforce having the focus on the capabilities of the characters, getting rid of most magic items is a good step, but better make sure your players will be happy with that approach !