If you're still using Boulder and Midnight Oil past Cyseal on Tactician your game will be much, much longer than 50 hours. Trust me on that.
The point is that you set up elemental effects for CC throughout the game, and then follow up with other moves and/or regular attacks. Boulder and Midnight Oil aren't used for damage, they're used for knocking the enemy down (the former) and setting up fires/adding slowing spots on the field (latter). With Midnight Oil only costing 3 AP, you still have room to use other skills or again regular attacks however you decide.
As soon as I got Ice/Air elemental
as soon as I got elemental summons
Goalposts moved.
Your argument after 2 pages is now that only the highest level spells are useless
high level spells are much more powerful than the low level ones..
And guess what the most of the actually powerful (*cough*useful*cough*) skills/spells are? I'll list them:
Teleport
Blitz Bolt (aim at water = stunned enemies)
Bitter Cold
Rain
Piercing Ice Shard
Any Fire spell that can set oil and poison and shit on fire.
Boulder Bash
Walk in Shadows
Charming Touch
Battering Ram
Cure Wounds
Goalposts moved.
If your argument is that their aoe is too large and unpredictable, I don't want to see you use Rain ever again.
Rain is quite predictable. It makes every single member of the fight Wet whether or not they are in a puddle, so it debuffs all fire casters/elemented-enemies, adds 30% chance for stunning, makes it a lot easier to freeze (chilled + wet = frozen). If your plan is geared on stunning, you can teleport the enemy into water puddles as necessary. You can Air Shield your own party member, and keep track of the turn order and including it in your plan on when to cast the subsequent Air spell (or shoot it with an Air staff). And/or you can have Rain on multiple characters for redundancy (redundancy is how one manages unpredictability); the benefit-to-cost ratio is worth spending one point in Hydrosophist even if a character's not built as a mage.
I guess you never end up stunning one of your characters because it's still beneficial since you stunned 5 other dudes.
Nope, because my stun-targets are high priority enemies such as spellcasters that can heal and/or crowd control, highly damaging enemies - especially those outside of easy reach, etc.
Then I weigh whether or not I need the resources (skills, damage, role) my possibly-stunned character provides, compared to the threat of said enemy/enemies. Also included in that decision is considering whether or not my character is susceptible to other, non-stunned, enemies damaging him and possible killing him.
The entire game is about managing the unpredictable nature of elements to mostly hurt the enemy.
The game is about setting up the playing field to be favorable to your party and your plan on how to use elemental effects for crowd control. Risk management.
Using Piercing Ice Shard to freeze multiple mobs is not unpredictable if it's ~100% chance due to your stats. Especially if they're already wet.
If I'm really going to be stunning 5 dudes with 1 of my characters within the AOE, I'm gonna be putting Air Shield on my character so that he doesn't get stunned.