I will elaborate a bit more on my examples.
When I look at spells, it does not feel that their effects are balanced against a spellcaster who did not know the creature’s defenses.
Instead, it feels like spells are balanced against:
- a Spellcaster who knows the creature’s weakness (either because they spent an action on Recall Knowledge AND succeeded on the roll; OR because they already know most of the creatures in the Bestiary); AND
- has a spell of the appropriate type prepared.
Likewise, it does not feel like damage spells are balanced against weapon attacks. It feels like weapon attacks are balanced against a spellcaster who used a feat to get trained proficiency with a bow and uses their third action to shoot a bow at 0 MAP (after casting a non-attack roll spell with their first two actions).
Likewise, the wording of certain spells. Unseen servant seems to have been designed with the presumption that the spellcaster is using him as a trapspringer and to break action economy in combat, not that the principal use is for the unseen servant is to pitch a tent and start a fire after a long day of adventuring.
There is nothing wrong with presuming that the players will know all these old dungeon tricks (or will simply crib them off an internet guide), but it does make it feel like the game is balanced against those that don’t do this.