I'm a little late to the party. The random element here is a seems like a headache for a lot of people, which is understandable. Speaking as objectively as I can, this randomness on such good effects is going to scramble the "meta" of best in slot items, making it so more total endgame items get used. This is good.
The biggest downside is that this hurts the players looking for feedback on how to improve their character to the point of competing in the game's hardest content. With random elements like the Gem of Many Facets, and now more so with this deck, our gearsets might not be something we can even recommend, since they're using pieces that have a 1% chance or lower of being obtained.
I know you could simply just run the next best set that doesn't incorporate these items, but that wouldn't cut it for a lot of players. As a DC caster main, I feel far behind other casters when I can't match their DCs, and an item likes this feels aimed to gate keep layers who don't participate in a luck based grind.