Piety as an ancient SP tree is quite good, but is limited by several things that Liberty and Tradition aren't:
1) There are no Piety SPs providing happiness.
2) Piety depends greatly on having a means to actually generate faith. Be it a unique ability, building, or unit, or a lucky natural wonder nearby, or a wide-enough civ fast enough to have a good number of shrines and temples up, whatever it is, you may not really have it until mid-game, by which time there may not be a religion left to found depending on the difficulty level.
3) Piety does very little to help you expand wide or grow tall. Liberty provides a settler and boosts building production; Tradition closer boosts growth via free aquaducts in the first 4 cities and +15% growth boost.
Piety is really only best when taken first under fairly specific strategies, a few of which include:
* Egypt taking Piety to crank out Burial Tombs to help go wide
* Mayans taking Piety to crank out their UB and get great science from a wide strat right away
* Siam going for the incredible (and exploitative) Wat-and-University combo; even when fixed, buying Wats with faith will still be pretty powerful
* Going for an early reformation belief (personally, the missionary conversion of barbs is very powerful in many cases)
1) There are no Piety SPs providing happiness.
2) Piety depends greatly on having a means to actually generate faith. Be it a unique ability, building, or unit, or a lucky natural wonder nearby, or a wide-enough civ fast enough to have a good number of shrines and temples up, whatever it is, you may not really have it until mid-game, by which time there may not be a religion left to found depending on the difficulty level.
3) Piety does very little to help you expand wide or grow tall. Liberty provides a settler and boosts building production; Tradition closer boosts growth via free aquaducts in the first 4 cities and +15% growth boost.
Piety is really only best when taken first under fairly specific strategies, a few of which include:
* Egypt taking Piety to crank out Burial Tombs to help go wide
* Mayans taking Piety to crank out their UB and get great science from a wide strat right away
* Siam going for the incredible (and exploitative) Wat-and-University combo; even when fixed, buying Wats with faith will still be pretty powerful
* Going for an early reformation belief (personally, the missionary conversion of barbs is very powerful in many cases)