Havent seen an AP champion banned in a while

It's not as surprising as one might think: with five bans I usually see each person banning something for their lane, or something like Cho'gath who's considered really strong at the moment. The vast majority of AP damage dealers are in one lane, and if none of them are considered overbearingly strong the mid laner might burn their ban on something they don't like playing against (often an AD assassin or Yasuo) or throw a ban at another lane or a power pick.