I'd be curious which spellcasters you think are far more effective than wizards?
At low level?
Bards for one. They have several of the Wizard spells (Charm and Sleep and Thunderwave) plus Cure Wounds, Healing Word, and Faerie Fire. At second level they have Shatter, Invisibility and Hold Person, and the ever cool Suggestion. And Vicious Mockery mostly means that they can potentially defensively lock up one foe for a goodly portion of a fight.
They also tend to have basically as good AC without using up a slot for Mage Armor, and tend to fight slightly better with weapons.
Above 4th level, though, Wizards easily win out (although Web does give the Wizards a lot of utility even at level 3).
Druids get Entangle/Thunderwave (plus Cure Wounds, etc.) at level one and of course, Bear form can be huge in combat.
And a Tempest Cleric seems to be able to hold their own as well as a low level Wizard since they have Fog Cloud for the defensive requirement, their normal Cure/Buffs, and Spiritual Weapon/Spirit Guardians for extra damage. Wizards have to cast both Mage Armor and Shield to get up to Cleric AC levels (and then only briefly) and are nowhere near as effective with weapons.
All of these classes are more effective than wizards at low level. They might not be as effective in one single situation that one single wizard spell is perfect for, but overall throughout the adventuring day, they add more to the group, kill more foes, take less damage, and overall just get more done.
The main thing that Wizards have going for them are Familiars (and the Sleep spell

For example, most familiars have an intelligence of 2. That's not very bright. So if the DM lets the player send his familiar out 3 miles and report back that 8 orcs are on the way, that might be a bit more than a familiar would actually understand. A familiar might not recognize a difference between a dozen orcs or a dozen deer or a dozen centaur. It might not recognize the difference between 4 orcs and a dozen orcs.
Wizards also have some versatility that the other classes do not. But most of this tends not to occur in game since the wizard player does not necessarily have the PC learn or prep the situationally dependent miscellaneous spells a lot (like Comprehend Languages, or Detect Magic, or Unseen Servant). The class has the spell, but the PC often does not.
This all goes out the window at level 5. Once Wizards get Fireball, they tend to take a major step forward.