Dragon doesn't need "a better buff" in s6
It needs global gold back. Maybe not the same but with each buff it should include increasing gold amounts for each dragon taken. Riot says people skip dragons and take towers instead. This is because while it may not be team deathmatch, Getting kills and towers are the name of the game.
The reason dragon worked so well before (even CLG refused to contest dragon) is global gold means everyone on your team getting benefits.