Are full casting progression and high tier characters overrated?

[King of Nowhere]

1 - Animal Companion gets Share Spells, much like a Familiar. If you're a Druid riding your dog / tiger / fleshraker into combat, you can use self-only buffs on yourself and your pet beast, but not on your pet Fighter.

2 - Most Fighters don't qualify for some of the better Druid buffs, stuff like Animal Growth or Greater Magic Fang.

ok, point taken. I don't know much about druids, as I was never comfortable with the class (guess because it's much weaker without all those stuff, and with all those stuff it becomes so good it feels like cheating).

Still, the fighter has a lot of buffs available from other classes. admittedly, it doesn't have animal growth, and enlarge person only provides a +2 to STR, not a +8. greater magic weapon/vestment is there, however. the point is that the fighter should also be buffed. otherwise, as said before, the fighter without magic support is useless.

There is also the point, when discussing multiple buffs, of the effect of losing said buffs to a dispel. Yes, I am aware there are ways to pump your caster level so high that you become undispellable, but most DM won't allow too much CL-increasing cheese; if they did, it costs resources that are not spent at buffing the animal companion. And a fighter is less buff-dependent than an animal companion.