Wrong idea. Keep titles for 2s, but make titles in 3's more available.
Make rating requirements, not place/number requirements as it is now.
This what I'm gonna say is just an example, not a real opinion:
Let say 2v2:
R1 req would be 3k.
Glad range would be 2.9k.
Duelist 2.8k.
Rival 2.7k.
Challenger 2.6k
In 3v3 'tho.
Make Rating requirement alot lower, almost twice as lower. That way, players would feel 3v3 is easier to get titles in because it is less inflated, lower rating requirements and easier titles. Then the bracket would get more inflated and populated.
This however is just me talking. Feel free to disagree. :)