Okay. Let's dig into this then. To what degree are these martial/weapon-focused/etc. classes "broadly comparable" with these spellcaster/magic-focused/etc. classes? I won't bore you with the details, but I've crunched some numbers here. If we focus only on class and ignore subclass, at 5th level a Wizard's damage output (assuming all spells are spent on damage) is in fact nearly the same as a purely damage-focused greatsword+GWF Fighter (~88.80%), and better than the Dex+Rapier+Shield+Duelist mixed-defensive Fighter (~106.35%.) While Battlemaster allows the Fighter to pull ahead relative to a subclass-agnostic Wizard, strong Wizard subclasses like Diviner and Bladesinger completely fill or even eclipse that gap. The superior spells (and larger amount of spells) by level 8 totally outshine the benefits of the bonus ASI unless it's very specifically spent on a strong feat, and even the extra Superiority dice can't keep up. I'll need to do a more thorough analysis for 11th level because there's a lot more math involved (more spells, more spell levels, more attacks, etc.), but...frankly it doesn't look good.
I assume something like 8 encounters per day, 2 short rests per day, 3 rounds per encounter (24 per day), and "nominally medium" encounter difficulty?
Do you account for "damage received/healed" at all? (A level 5 fighter in plate is going to have more AC and soak than a level 5 wizard is).
Like, a PAM+Spear fighter hitting 65% of attacks with 18 strength and 14 con and a shield has 20 AC, 44 HP, and 3d10+15 (31.5) self heal, does 2d6+1d4+18 (27.5) damage if everything hits from an action (+9.5 on a crit). At 24 rounds + 3 action surges this comes to 27*.65*27.5+27*.05*9.5=495.5 damage budget.
A wizard with 18 intelligence and 14 dex and 14 con has 12 AC and 32 HP. Firebolt is 2d10 (11) with the same 65% accuracy 5% crit for 184.5 baseline. Each round not using firebolt costs 7.7 less baseline damage.
A 5th level wizard has 4 1st level, 3 2nd level, and 2 3rd level spells, and can recover 1 3rd level spell per day. Assuming each of those takes an action, the wizard casts 4+3+3=10 less firebolts, meaning only 107.5 firebolt damage.
So the fighter gap is 495.5-107.5=388 damage to be made up with leveled spells. Lets do this!
A fireball does 28 damage, 2 targets, 60% failure rate. .6+.3*.5 is 0.75 average multiplier, *2 is 1.5. So 28*1.5=42 damage per fireball. x3 is 126.
388-126 is 262 gap remaining.
For 2nd level spells, lets go with scorching ray and shatter. Shatter is 3d8 (13.5) aoe for 20.25 damage per cast. Scorching Ray is 3*2d6 = 6d6 for 14.7 damage per cast. Shatter wins.
3 casts of shatter is 20.25*3 = 60.75 damage. 201.25 gap remaining and only 1st level spells. This doesn't look good for the wizard.
Burning Hands is probably our best choice. 10.5 damage AOE for 15.75 damage per cast, times 4 is 63 damage.
136.25 damage gap remaining.
Huh.
Fighter total: 495.5
Wizard total: 359.25
Wizard: 75% of duelist fighter damage
Fighter total HP (including half rounded up HD) per day: 95
Wizard total HP (including half rounded up HD) per day: 48.5
Wizard: about 50% of Fighter's durability
Wizard AC: 12, but can boost to 15 by losing a burning hands (probably a good idea).
Fighter AC: 20, reduced to 18 if they want to avoid disadvantage on stealth.
No subclass used for either.