I've seen a lot of control and damage spells be highly useful in PvE and in PvP. Even a 5% chance to fail something is not one the target wants to have to repeat. In my experience if a roll can be failed, you can count on it happening.
Mages have consistently put dungeons higher level than them through the ringer by targeting the weak saves of the enemies there. Warmage and warlock made it even more insane.
At some point spells get so good that teamwork is undermined and party makeup doesn't matter too much.
The classic "meta" of buffing classes doesn't exist because their offensive spells are weak. It's because the rest of the server can't really do dungeons cost efficiently or even safely complete them without the help of the classes that can solo farm those same dungeons.
I think part of that stems from the economy. If you took a Fighter in their mid-teens and they had a cheap supply of potions, there's a lot of content that they can genuinely solo without a second thought. However, it's financially unviable. Ninjalooters just solo content for the things most people want, since you can get XP in many ways other than dungeons, so they too, can solo.
Idk what it's like today, but trap soloing used to be a big deal. That's how they used to ninjalooted Sithicus before the rework some years back.
At the end of the day, it's a conversation of money vs. xp for solo'ing, if you're stealth-capable, you can get all the money, but little to no XP. If you're a Fighter, you can go Geralt of Rivia and chug and glug in most dungeons, but not ones which include dispelling enemies. If you're a Monk you can just run through the dungeon, and if you're a Monk in the Red Vardo, you can run through the dungeon and pick most of the locks and steal everything then run back out, possibly stealthed as well.
There's a lot of creative solutions on the server depending on just what you want to get out of it, and that's before we stumble back to higher-level characters clearing out low-level dungeons solo to take the loot, which has also been a thing, and to my knowledge isn't exclusively against the server rules (or wasn't before,) so that's also an option for money without blowing tonics.
PoTM tries hard to avoid it, but where there's a
whip will there's a way.