Limiting itemization

I was thinking if it was possible to limit itemization based on the champions role (for example: Mages won't have access to tank items like frozen heart or AD items like Infinity Edge), I believe doing this will reduce the amount of trolls in ranked games.

Edit: This would also solve some problems quickly, instead of fixing everytime a champion's ability just because some Items aren't supposed to be build into it and makes him too overpowered, limiting those items would solve it (last season tank ekko for example).