My experience with 3e might not be typical, but here goes.
First, almost everybody was a spell-caster, right down to saloon girls and probably that third-level baby in the perambulator. It was like RuneQuest, man.
Second, everyone was spending most of every session waiting for his or her next turn in combat. That might take five or even ten minutes per round. So, one might be inclined to go for what was going to be more mechanically interesting (synergistic feats and skills and attacks of opportunity and fine print exceptions and whatnot). After a while, it could even get boring to "spam" flaming sphere. Also, a quick finish to a fight typically just meant moving on to... yet another fight. They tended to run into one another without much distinction.
Spell-casters (which meant pretty much everybody who was anybody) tended not only to have access to pretty respectable mundane gear, but to be able to make magical stuff in a process that was pretty trivial next to the old way. It was not so trivial they were keen on spreading it around, though, hence another inducement for everyone to go into the business for himself.
Besides "craftily" ornamenting ourselves like Christmas trees, we also found goodies in treasure. Those tended to be just the sort that would come in handy down the line, the way the DM set up things.
So, with magical defensive gadgets and magical weapons, plus feats and skills (and a rules-lawyer on retainer), we were pretty well set up to shoot and stab in between zapping with spells.
I seem to recall spells being mainly for "buffing up" before a fight, and securing advantages in the first few rounds. There would typically be one person who kept on concentrating on spells, but I think the one varied from fight to fight.