What we need are seasons with some sort of cosmetic reward for your placement. Maybe like a tank skin or decal or some medal to display on your playercard?
You could have an overall ladder and seasonal ladders with separate ELO. Let players choose whether to play the seasonal ladder or oldschool ladder when going into automatch.
But maybe we don't have enough players for that - might make queues a nightmare
+1
This right here is how it's done. Starcraft 2 uses a seasonal ladder and ELO system that resets approximately every 4 months. It ensures competition stays fresh and new players have as much chance as established "pros" to reach the top of the leaderboards.