The buffs it offers are underwhelming, especially when youre paying 3 to equip
This problem is super easy to fix: either Wizards could have downshifted the rarity on Mystical Archives everywhere while keeping the distribution the same (e.g., make Crux of Fate a rare and Faithless Looting a common but still have them show up at the current rate in packs), or Wizards simply could say, "You can acquire these cards with a wildcard based on the cards' true / original rarity, rather than their inflated Mystical Archive rarity." Second, several of the rare or mythic Mystical Archives already exist on Magic Arena at lower rarities
I guess everyone got so blindsided by Ocelot Pride that we totally missed this quote-unquote hidden gem
Playing a commander that's just a one or two time mana generating cruise missile probably isn't for everyone, but I can see some merit for hyper aggressive strategies that want to set up fast and hard on turns 3-4 for a really stupid midgame power spike
The plane of Dominaria was the birthplace of the shadow mechanic, so maybe well see shadow again on a return visit, but its a fairly small possibility because R&D avoids putting parasitic mechanics (i.e., mechanics that only work with themselves) in modern sets
Each deck has its own strengths and weaknesses, with one clear powerhouse among them