It's currently a close second behind Tradition; but that difference is enough for me to never pick Liberty.
But both Tradition & Liberty are miles ahead of both Piety and Honor.
If I were trying to balance the opening policies I would:
1. Minor nerfs to Tradition by downsizing the finisher growth bonus to all cities down to the first four cities (same ones getting free aqueducts) & remove the city bombard bonus.
2. More significant nerf to Monarchy: bonus happiness & gold for every 3 citizens instead of 2.
3. Nerf to Liberty : Remove the free Great Person from finisher. Relocate the free GA to the finisher
4. Minor boost to Honor: One of the policies would get the city ranged bombardment bonus.
5. More significant boost to Honor: Move the City Walls happiness bonus from Autocracy back to an Honor policy.
6. Boost to empires going wide regardless of policies:
National wonders would require flat 4 copies regardless of size of the empire.
7. Boost to later city founding: For cities whose settler is built starting in Medieval era, have the city start with a free Granary. For cities whose settler is built starting in Industrial era, also include a free Monument & Shrine. Starting in the modern era, also include a free library.