You need to come soloing with me at Stanage sometime jwi.
But seriously, if we define perfection as unattainable then I think that maybe isn't a very useful definition. An analogy: if you watch Ronnie complete the fastest ever 147 you could find the odd point where shots dould have been executed better. But you could argue those mistakes force harder shots which actually raise the overall level of performance, which is the greatest there's ever been. Is that not therefore perfection? And, crucially, he never runs out of position, which is not a pinpoint thing but continually putting yourself in a position you can work with. I think these ideas transfer to climbing quite well.
Personally I find onsight performances the most satisfying because they involve creativity which adds a dimension. So rather than nit-picking precision on a redpoint, for which the music analogy above is appropriate (jazz aside obvs), you can take a broader view that consistently hitting the sequences right first time and never running out of position or even climbing yourself out of an error is a thing close to perfection, by which I mean like Ronnie it may not have been bettered.
I'd also add that an important dimension was missed from the OP, which was that Varian did not simply find a problem that tested him to the utmost, it was a new problem at a crag he has largely developed himself, in his extended backyard. In the interview I think it's clear those are as important to his idea of perfection as the technical challenge.