On the other hand, multiple high-tier Skirmish Noetics can be quite a pile of fragments in Skirmish. 1-1-1 runs on the other hand, considerably less.
Faithful legs beef up how many Noetics show up. II adds one, III two...up to V being 4. They also up the fragment rewards as well. Rala/Cirdas ones go 100-200-300-400-500 per from I-V, Yorica 150-300-450-600-750.
So if you do a I-I-V on Yorica? That's 750 x 5 = 3,750 fragments from Noetics alone, plus whatever from kills and trading in junk NQ stones for more fragments at the Inventor's. And of course, a higher torso piece adds more Noetics (though not improving them).
Rewards for fragments tend to be puny owing to folks using the weakest parts possible to build a KI, not because the rewards aren't there.
Edit: And heck, higher tier Visages often skip the whole process because they up the odds of +1/+2 stones simply dropping to begin with.