Frankly, Strixhaven was a great draft format but its impact on constructed has been almost nil. Other than
Magma Opus, I can't think of any cards from it that really see play.
Strixhaven has actually had a pretty decent impact on eternal formats.
Expressive Iteration is one of the top 30 most played spells in both Modern and Legacy right now, and it's the 5th most played spell in Pioneer.
Prismari Command is seeing quite a bit of play in modern as well as the U/R Dragons deck in Standard.
Sedgemoor Witch has also seen a decent amount of play in
Young Pyromancer and
Dreadhorde Arcanist decks, although those archetypes aren't really popular enough to push it in to the upper echelons of any eternal format
.
As for standard, Strixhaven will likely have a larger impact once Throne of Eldraine rotates. That set is full of great removal that is currently being overshadowed by the efficiency of
Bonecrusher Giant and
Brazan Borrower and the irritating card advantage of
Emergent Ultimatum.
Elite Spellbinder and
Blade Historian currently see some play in Winota decks, though
.
I don't think that really detracts from your larger point about Champions of Kamigawa specifically, although Strixhaven was not a great comparison point, it was honestly a pretty great set even by today's standards.
I really don't know if they understand this fundamentally. For years Maro has been pretty annoying whenever met with Kamigawa questions and refusing to acknowledge how shit the mechanics were for the set and how that might have influenced how parts of the playerbase felt. Legendary subtheme wasn't implemented well until Dominaria, the keyword mechanics for the block were mostly awful and didn't play well with the rest of Standard, and to top it off it was sandwiched between two VERY powerful blocks.
Their "official" discourse on Kamigawa as a whole has felt very disingenuous over the years.
I think calling MaRo's answers regarding Kamigawa "disingenuous" is a bit misleading. A lot of people like the Kamigawa block, and have wanted a return despite the "badness" of the last two sets forever. But bad cards aren't the only thing that deters a Magic set from being revisited. After all, Born of the Gods and Journey into Nyx were worse than Betrayers of Kamigawa and arguably even Saviors of Kamigawa, but Theros still got a return only 6 years after the curtains closed on the original block.
Mark's discussion of aspects of the Kamigawa block other than the "shit mechanics" is likely due to the fact that those issues represent a big barrier to world's return. After all, sets like Battle for Zendikar and Ikoria were awful from a mechanical perspective, but both sold extremely well despite the troubles. Kaldheim, while extremely underpowered, also sold really well and was enjoyed by a ton of players. And it's not like these sets weren't around at the same time as other powerful sets, with Battle for Zendikar coming off the heels of Khans block and Ikoria and Kaldheim following up Throne of Eldraine.
Kamigawa, though, sold awfully, despite Champions of Kamigawa actually being pretty decent. The problem was in part that not everyone was able to fall in love with the world. Kamigawa's lore was really cool, but it isn't as accessable as other facets of the multiverse. The heavy Japansese influences weren't super well known to audiences outside of Japan, and that hurt the block in some ways. It wasn't like Kaldheim where almost everything had a fairly direct comparison to the most commonly known Norse mythology tropes, and it wasn't a return to a world already beloved setting like Zendikar. Kamigawa was a wierd world that tried to do it's own thing to stand out, and it just didn't hit the mark with everyone.
I'm not saying the cards in the Kamigawa block being worse than those that surrounded it
didn't have a negative impact on sales, but I am saying that Mark mentioning the other barriers to a Kamigawa return is not disingenuous. The handling of the setting turned off a lot of people and that really hurt the chances of a set return for those who love Kamigawa.