Odhanan
Adventurer
When your character is balanced on a per-encounter basis, I suspect the game gets less interesting -- at least for me.
I understand the concern, and think it's true in essence. However, a "per-encounter" design would also mean a "per game session" correlation. A "per day" ability translates in my games as "per game session" in fact. This means there is still resource management per encounter in practice.
Point in case: I have a PC who died and became a ghost (as per Ghoswalk Campaign Option). I needed the PC to be able to switch between corporeal and incorporeal states since there's no "manifest ward"/gimmic to allow switches with Ptolus. I designed a magic item (bracers) that allow a switch from corp. to Incorp. OR the revers three times a day. It created some problems almost instantly, and I changed the ability to 3/game session. Since then, it's been working admirably, because the time management is based on a concrete game aspect instead of a fluctuent element of the fiction.