You don't exclusively need them. Yuzuru (and anyone else) can grow as an artist without new programs. Chronological growth itself will be a part of this, as you would gain more life experience with it. However, how are you supposed to achieve true growth if you don't explore? The Chopin program, for instance, was first choreographed when he was 19. Had he left no reservoir of art unplumbed that he repeated this program for two more seasons? A new program in itself would have been a new life experience -- something he could have learned to perform really well over the new seasons. With Chopin, sure, maybe he did mature as a person and made the program more mature as he did, but it was never a two-way street after the first season.
This isn't to say people should NEVER repeat programs, however.
Personally, because Yuzu had a different free skates up until the Olympics I always found he had enough variety in his competitive programs to give me the impression that he has a large range of expression and that he's grown artistically. The third time repeat for Ballade no. 1 as I mentioned was more for practical purposes rather than artistic. It's a decision that is understandable in a sport and particularly in an Olympic season when you want as much of a sure thing as possible. Even with that, I think he still worked on elevating that program beyond version 1 and 2 (I guess there were really a total of 6 versions of this program - two in 2014/2015, and two in 2015/2016 - although we only saw 5 after his injury - it's been a turbulent 4 seasons). Each of us has their own idea about what constitutes artistry. For me, artistry in competitive figure skating is in how skaters fuse the technical skills of the sport with music and performance so that you don't notice one over the other and I think Yuzu's demonstrated growth in that aspect over the last 4 seasons. Now that the Olympics are over and he's reached one goal, I'll take his comment about skating programs he wants to skate to to mean he'll feel less need to be practical and allow himself to do whatever he wants (although in the back of my mind I wondered if what he really wanted was to skate to LGC again....
He performs it well, it's not like he isn't a competitor. It was just never an artistic statement big enough to be repeated those many times.
I don't agree with this at all. Faux dramatic programs are something I believe the audience to universally hate. The best thing about Yuzuru's R&J1 is that it takes time to build AND hold up a character arc -- that's what I mean when I say it is complex. Seimei, on the other hand, is quite shallow in comparison -- it's an attempt to build a character again, but it has flaws there because the build of the character just stays on a plateau. Compare it with R&J1. On the other hand, H&L is now something different -- there ISN'T necessarily a character there, just introspective movement, which the audience can absolutely connect to.
Slightly off-topic again, but I actually find a lot of fans on Goldenskate seem to LOVE faux dramatic programs. For some that is what defines artistry and expression, so I actually don't think it's universally hated. People probably have varying range on what they consider to be over the top. I just know my tolerance for that type of expression tends to be low.
Back to the topic at hand, it's interesting how different people view the same program. For R&J1 and Seimei, I never thought of either programs as being about the character as it was about a story. Sure, maybe R&J1 was a program where the story focused a bit more on the character of Romeo, but to me it had to do more with the tale of Romeo and Juliet than it did with Romeo himself (I don't think Romeo as a character develops a whole lot in the original play either). Seimei as well, despite being named after a person/character, felt more like the weaving of a spell and a ritual than about the titular character. I think when Seimei was first debuted Yuzu deliberately named it and wrote it as "SEIMEI". In his talk with Nomura Mansai he said it had the double meaning of the person (Abe no Seimei) and "life". I've always seen the program as spell to create life/light where there is darkness. My take is that the choreography for Seimei is more nuanced than it was for R&J1. There are tiny details in the way Yuzu holds his back, his gaze, and positions his arms and hands through the program that are very deliberate that help to create an amazing atmosphere which culminates in the choreographic sequence. R&J1 was more about passion and reckless violence of youth, it's exciting and engaging in a very different way but I'm not sure I'd call it complex as I find its story to be pretty straightforward. It does however have very interesting and gripping moments in the choreography. To each their own, but there's something to love in all his programs (even the David Wilson ones that rank lower on my list).
Speaking of exhibition skates, I know that I said Requiem at Boston was one of my favorite exhibitions, but prior to that I actually wasn't a huge fan of this program. The performance at Boston made it special and is really the only version of it I watch. It was during the latter half of the 2015/2016 season as well when Yuzu also skated Final Time Traveler again in a show. I actually am not a huge fan of that program either, but when I saw him skate it again I remembered thinking it looked so much better than before.