Any other 2nd level ability damaging spells? Chill touch only does 1 Str on a failed save, but that is 1st. Touch of idiocy is a penalty to 3 stats, not damage. Feeblemind doesn't even do damage. Ego whip does 1d4 (save for half) Cha dmg.
Assume Foolish Fighter has a Fort +5 and Will +1 at 3rd level (14 Con, 12 Dex, and 10 Wis). Our chaster has a 15 Caster ability, so a DC 14 save. So, 24% of the time, Foolish takes 8 dmg to two stats, 36% takes 8, and 40% takes nothing, for an expected loss of about 3.5 to two states. In comparison, Foolish can expect to take 1.5 to one stat from Ego whip (and one that does not affect subsequent saves to the ability). A CR 3 shadow vs Foolish with its 1d6 Str touch attack at +3 expects to do 1.2 Str damage. Thus, in comparison to other CR 3 attacks, PA is quite stronger (unless my discrete conditional expectation is off, which it could be).