Yep. This is why Battlemasters and Paladins (and other spellcasters) are often more effective than Champions. Over the course of a long adventuring day, the extra crit chance of the champion may mean that they technically deal more overall damage, but the ability to dump resources when and where you really need them is more valuable.
Champions are a bad example here.
The problem is that the "braindead" Battlemaster build (use dice only on crits, when missing by 1-3, or on a ripose/brace reaction) gives more overall damage in an adventuring day than the Champion gets, at least until high levels.
So comparing the Champion to the Battlemaster means that the BM
both has the ability to focus its resources, it
also has a higher baseline output.
Using some scripts to simulate it, a Braindead BM using 1 superiority die in an encounter (1/3 of its short rest resources) is
better than the Champion, sometimes by a reasonably large margin (like, 1.5x as large as the difference between a Champion and a fighter-without-subclass). And if the BM uses 2 or 3 dice, the gap is even larger.
In order to make a Champion that matches the BM using only 1 die, I had to add to the Champion "when you use your second wind, you get a weapon attack, and you roll (fighter level/2) extra d10s". With that large of a buff, the simulated Champion matched a 1 SD Champion. It was still outpaced by a 2 or 3 SD Battlemaster.
(These simulations where done at level 5. Builds where not optimized; precision attack, for example, is much better with GWM/SS, but I didn't use it; in general, BM would gain more from optimization. I simulated 2 characters (with that build) against a number of ape monsters (4-10), and measured % chance of TPK/% chance of losing a PC. All monsters and PCs focus fired. Action surge/second wind being used was either used or not in various simulations. Number of apes was tweaked so that the baseline fighters wouldn't win 99.9% of the time.)
The conclusions of the Ape-brawl simulations matches DPR calculations of Champions vs Battlemasters.
Now, last time I did the math, by the time a Champion hits T4 and you equip them with synergistic gear (like a flametongue) the gap has closed.
So, a greatsword flametongue does 21 damage/hit.
+11 to hit. Foe with 21 AC means a swing is worth 12.25 damage.
A "boosted" attack does 16.15 damage per swing.
At level 20, the BM has 6d12 superiority dice. Converting to damage:
Use for damage on a crit. 13 damage per SD, 0.05 dice/attack
Use when miss by 1. 21 damage/SD, 0.05 dice/attack
Use when miss by 2. 19.25 damage/SD, 0.05 dice/attack
Use when miss by 3. 17.5 damage/SD, 0.05 dice/attack
Use when miss by 4. 15.75 damage/SD, 0.05 dice/attack
Use when miss by 5. 14 damage/SD, 0.05 dice/attack
Use when miss by 6. 12.25 damage/SD, 0.05 dice/attack
Use with a reaction. Each SD does 16.15 damage ('boosted') - brace or riposte
Suppose you have 12 rounds of combat between short rests. Then if you burn more than 0.5 dice/round you'll run out.
If we use precision when we miss by up to 5, and on a crit, and get 1 reaction every 10 rounds (0.1 per round), this is 0.4 SD/round; with 2 action surges and 12 rounds of combat using 5.6 between short rests.
Damage per round is then boosted by an average of 6.6 per round by this "brain dead" use of SD.
The baseline fighter did 49 damage per round. So the BM was +13.5% damage over baseline. Over the 12 round short rest, the BM did 778 damage.
We then go to the champion. It adds 0.1 crits/attack, each crit does +14 damage on average, so +1.4 damage per attack. 4 attacks/round comes to +5.6 damage/round; an +11.5% damage over baseline. Over the 12 rounds between short rests, the Champion did 764 damage.
This gap is much closer than the same math at level 5, but still exists. It is only about 2%, which I'd consider not important.
The BM's ability to focus and optimize further is greater than the Champions ability to "last longer". The Champion does have another good feature (survivor) that the BM lacks on the other hand. And the +3 initiative bonus, other athletics bonuses, and the fighting style isn't nothing either.
At lower levels, where people are more likely to be playing, the gap is much larger. Hence my "you get an extra attack on a second wind"; this has a
much larger impact in T1/T2 than in T4, as in T4 you already have 4 attacks/round; adding 1 isn't a huge swing. In T1, that extra attack is significant.
(Braindead comparison at level 5: Using a Longsword+Shield dueling style and 18 strength, the baseline is +7 to hit/1d8+6 damage. Against AC 15 that is 65% hit chance; baseline damage per action is 14.1. Champion adds 0.45 damage per action; 3% boost. BM die on crit is 9 damage, BM miss-by-1 is 10.5, miss-by-2 is 9.2. Doing both is 0.15 dice/attack for +1.435 damage/attack, so 0.3 dice/action and +2.87 damage/action; 20% boost. At 0.3 dice/action can last 13.3 actions between short rests; good endurance. Large, noticeable gap here. Over 12 rounds the baseline is 183, Champion is 189, BM is 220. If you add in a Second Wind attack to Champion and +2d10 healing, +7.05 damage and +11 healing, which closes more than half of gap with the BM if you value healing anywhere near damage.)