Wizards and Clerics aren't Really dominant anymore.
Sorcerers are more popular than Wizards, and Warlocks are more popular than any other full caster.
Cleric was always more necessary than popular.

But, I seem to remember the Big 4 dominating class popularity polls, even quite recently.
Popularity doesn't always track mechanical effectiveness or class Tier or the like, though. The fighter topped the list of most popular classes in 3.5, when it was
Tier 5, just a step above hopeless.
3e had the infamous Hulking Hurler among other options.
And 4e was an odd duck for any kind of ranged Fighter, they couldn't even use bows with most of their powers.
4e had 4 full classes that were 100% martial, no casting. Initially, strikers - Ranger & Rogue - were given the ranged options, so you had a deadly knife-thrower and very potent archer at launch, and though it never did tackle the conundrum of what a ranged defender might be like (let alone an all-martial controller), the Warlord got a ranged option in Martial Power 2, as well.
"Fighter" in the usual D&D sense - the non-spell-using, non-magical, non-supernatural, weapon-user - in 4e, was the whole Martial Source, encompassing 4 full classes, 20 or 30 builds (sub classes), and over a thousand exploits (maneuvers).