I think that when I first read Piranesi, I never thought of LA-S as John Uskglass. I thought of him as Norrell. Yeah, he feels extremely different from Norrell. That, however, is the exact reason why I thought of him that way. In his function, he has the same role of Norrell. They both were believers of magic in a world in which magic was not something anyone really did, they both tried to learn about magic and bring magic back into the world. However, in many other aspects, they were the opposite. LA-S is different, unusual and contradicts anything considered socially acceptable back at the time. He spread his knowledge to a group of followers but his opinion is never socially accepted and he remains to be seen as a criminal and a madman. However, Norrell is rich and fits in his society perfectly. Unlike LA-S, he is much less charming and charismatic (those words do not belong in the same sentence with Norrell) and he does not teach anyone. However, he is the one who managed to make magic seem socially acceptable. Both are not able to comprehend the truth of magic in the end: LA-S never understands the House while Norrell remains stuck in his own limited world view.

In the end, in JSMN, magic becomes widespread but in Piranesi, magic remains something only a few cultists would practice and they are probably frowned upon for their irrational and superstitious activities.

I wonder whether this current states of both worlds are cause by the facts that in one case, the pioneer is socially acceptable and in another case, the pioneer is obviously not. I think Clarke used to say that only someone as boring and unthreatening as Norrell could bring magic back to England.