Always the same champions

I have been playing this game since season 3 and it was my go to place whenever i was bored. Games were diverse and you could see any champion. However now there's almost no diversity at all. It's always just the same champions over and over again. There can't be one game where i won't see a Lee Sin, Lulu, Zed, Kog'Maw and such. And whenever a new patch comes along these champions have barely got any changes if not any. Also what about the rest of the champion pool? When was the last time you saw a Nunu or Anivia or even Annie? Remember when Annie was picked as a support in every single game? Now you probably don't even remember what her skills are. And what happened to the supports? Nowadays people only play mages. These so-called "supports" are no fun to face and they're always there. I think what Riot should do is make it so that players can't play the same champion two games in a row and that only certain champions can be played in certain roles. You know, the roles they were intended to play. That would give a person even more reason to play different champions and auto-fill won't be as easy to get past by.