Keith Giffen sends Thanos out like a man in a pool. Next for the Cosmic Line would come The Annihilation Event in 2006, in which Thanos would play only a very minor part. He didn’t drop off the radar entirely though, as you’ll see over the next week or so. He just wasn’t a major player.
It’s almost as if he was on vacation, just like in this closing sequence from Thanos #12!