No one ever claims that casters cannot be DM fiated into needing other party members. But they are, as you clearly understand by your wide variety of anti-caster plot elements, the ones that require the greatest variety of and often the most heavy-handed methods of keeping under control.
My favorite style of casters are the 'hidden master' buffmonkeys. Any mundane scrub with a sword can deal HP damage, and while arcane magic can singlehandedly end encounters, that earns DM wrath who will then go out of their way to nerf the caster. So you load up with Haste, Stinking Cloud, Acid Fog, Enervation, Mass Snake's Swiftness, Ironguard, Brilliant Blade. You buy Metamagic Rods of Chain Spell. You prestige into classes like War Weaver, or if you're feeling merciless, Incantatrix. Then you throw out a flurry of buff spells that turns your entire party into near-unstoppable demigodlings, drop a few no-save crippling debuffs on the enemy, and let your 'meat shields' puree everything while you sit back and drink daquiris, safe in the knowledge that you were, as usual, the deciding factor in the fight, but you were smart and subtle enough not to brag about it. It makes your party members feel awesome because they're living wrecking balls, and rarely complain when you want to make them even better at their job, and it's actually more efficient than using your own spell slots for damage/summons.