See my post here
https://www.goldenskate.com/forum/threads/2021-22-russian-womens-figure-skating.88316/post-2869518
The question is not that judges/ISU don't care - they just can't have technical ability to do it and they don't feel any need to do it either since it brings nothing to the table in terms of money/popularity/tickets-selling.
That, and equaling prerotation with underrotation is not valid comparison as well. Prerotation is unavoidable to some extent while underrotations are not.
Hanyu and Aymoz have less than 0 degrees prerotation on flip and lutz. Muravyeva has 0 degrees prerotation on loop. Yeonjeong park has 0 degrees prerotation on toeloop. It’s possible.
Prerotation can't be seen by naked eye in real time while UR are often obvious.
The difference between Grassl and Boyang’s 4Lz is more obvious in real time than the difference between Kihira’s 3Aq at worlds 2021 and her rotated 3A from the nationals before.
Prerotation do not ruin visible quality of a jump (Samarin's or Valieva's quads are one of the highest ever jumps) while UR are often leads to fall, bad landing, step out etc. - resulting in spoiling whole performance quality i.e. PCS. Considering that many judging criterias are subjective things where beauty of element/performance is assessed - visible quality is the most important. Because skaters are selling their programs to viewers - not their jumping technique minutiae that can be seen only in slo mo.
Also, while UR is clear sign of low height or low rotation speed - prerotation is measure of how much force skater applied to attain peak rotation speed as early as possible and keep it as long as possible.
Karen chen has big jumps but frequently URs. Anna’s 3Lz and 3Lo are both smaller than Karen’s but she rotates them much more often because rotation speed which ISU does not consider to be a GOE bullet/part of the “beauty of the jump” like they do with size of the jump.
“URs lead to bad landing/falls therefore they deserve penalties because they ruin the beauty of the performance” the opposite is true, URs are called when the skater gives a beautiful performance so that judges can justify putting the favorites ahead despite inferior overall performance quality by saying “oh in slow motion review UR is visible” as if Kamila or Maia effortful takeoff is not also clear once in slow motion. Case in point Mao Asada 2014 Olympics free skate, Rika Kihira 2021 worlds short program, Wakaba higuchi 2021 IDF free skate = huge decrease in TES based on jumps reviewed in slow motion only so Sotnikova, Shcherbakova, and Kostornaia (and Yuna Kim) stay ahead.
It's not way to "steal" turns as it is with UR - it's way to generate torque force.
And UR is not a way to steal turn it’s just a way to absorb torque force.
Blaming prerotation for stealing is the same as blaming launching rocket for making crater in ground when rising in the air. It's just unavoidable derivative of that technique - not its main goal.
Goal is to make jump easier to rotate...once you leave the ground you are fighting gravity force and more rotation in the air increases the force felt on landing.
Main goal is jumping with means of rotation speed and not brute strength. Which can't be attained with classic technique - with its usual delayed rotation (1/3 of jump's time is wasted to mostly lift the body vertically up in air with slow rotation - and peak rotation speed is attained only when skater is going down already). Making complex jumps with classic technique available only for very few very strong unique people. And that is not what good technique should do. Good technique is efficient technique - that will make hard tasks easier for weak people.
Yes, rotating a triple or quad is easier for skaters who complete the rotation on the ice after landing. UR is efficient so UR is now good technique.
From that sense Anna's quads are pure technical jumps done with means of precision and timing while Nathan's quads are athletical jumps done mostly with exceptional strength of muscles and ligaments working against highly ineffective classic technique with its delayed rotation - created specifically for single and double jumps.
What you are suggesting is basically denying any progress for optimizing technique akin to banning jumping with back in "high jump" discipline or banning start from crouching position in sprint discipline - because our ancestors didn't do it like that and did it more "fair". Then you should advocate for banning modern jumps like two-foot salchovs or loops - or triple axels with using toe catching ice as leverage. Noone jumped single jumps like that in classic era, right? But proclassic crowd are only against one certain optimization to make complex jumps more stable and accessible - while other much more obvious optimizations are seen as nothing wrong.
Pro classic crowd are against two skaters getting credit for the same thing when one does it harder yes. Nathan or Boyang or Zhilina 4Lz technique is also totally optimized compared to to the original 3Lz jump in terms of precision and timing and yet is still much harder than Anna 4Lz or Grassl 4Lz technique. Next you will tell us Kvitelashvili’s 4T technique (totally different from his own 3T technique) is just “optimized” and every skater should do it and I will say - yes every skater should do it so long as ISU credits it as a 4T because it is obviously easier to learn 4S and land it three times than it is to learn two different quads. The buck should stop at ISU and they are responsible for fixing such issues not Kvitelashvili.
By the same logic about what is most “efficient” we should oppose the Zayak rule because it is more efficient for a skater to learn one triple lutz and repeat it seven times than it is to learn 5 triples, and so long as they land it cleanly it doesn’t take away from “the beauty of the performance.” No, the buck stops at ISU and they should be responsible for ensuring relative difficulty of learning all triples is rewarded which is why they introduced Zayak rule.
Then you should stop to label her jumps as "full blade assist". To call things for what they are and do not call for what they are not is simple. Give it a try

Then noone would argue with you anymore.
In this case I agree yes they should stop labeling Anna’s jumps full blade when they are obviously not on the level of Khromykh or Kvitelashvili.