Weapon specialization was the same bonus no matter what. It only changed what slot the bonus applied to, same with mastery and such. There isn't much difference between a longsword wielder with mastery and a battleaxe wielder with mastery... other than one could have +5 weapons and the other capped at +3.
Depending on your chosen weapon, weapon specialization gave you a different attack rate, and bow specialists gained point-blank range. Other differences between weapons were damage (also depending on the opponent's size category), speed factor, reach and (optionally) bonuses vs. different types of armor. Certain weapons were very effective to discourage charging enemies, and Combat & Tactics also introduced knockdown rules which favored the usually low-damage bludgeoning weapons. Also: firearms rules, if the DM allowed them

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There were differences, just not to the same extent as in 4e. (I've never played 3.x, so I won't comment on that edition.)
And that's just the weapon-based stuff. That doesn't take into account difference in -styles- of combat.
I'll grant you, fighter kits did something to give options to players in terms of bonuses they could add on once in a while, but it really wasn't that drastic... not even as drastic as taking Cleave vs Reaping Strike. The two at-wills you take do more to determine a combat style than anything second edition cooked up.
To be fair, you're comparing two editions that are almost 20 years apart; of course 4e improved on its predecessors and does things differently.
Still, 2e's early fighting styles had "drastic" effects. For example:
Weapon & Shield spec: You get an additional attack with your shield so you can parry an enemy attack or knock someone down with it.
Two-Hander spec: You're faster with your two-handed weapon. This made a lot of difference in fights against spellcasters (higher chance of interrupting their spells).
Later styles included e.g. horse archery.
And from what I remember, most kits gave permanent bonuses. The swashbuckler had good reasons to stay in light armor (AC bonus), and bonus weapon proficiencies don't exactly count as "once in a while".
And Player's Option... sucked. Yes. It sucked.
I disagree.
