Maybe I don't understand why I am supposed to be so impressed with this. A computer already has all of the math and probabilities right there in the code - I've been losing to computer players all of my life, so a CPU's ability to just stomp me to death with the most optimal moves isn't exactly a new experience for me no matter how you cook it up.
For me the hallmark of a good CPU player is how badly it can play. Does it make interesting choices? Does it respond to my choices? Do I feel sufficiently challenged?
I actually have been playing the Dominion app for a few years now. The AI does occasionally exhibit some interesting and novel combos! But for the most part it still just latches onto the most optimal set of moves it can find and goes for the kill.
Even at lower difficulty settings the CPU has no personality and can just be brutal. The AI also still exhibits some of the same old-school bugs where it latches onto a losing strategy and doesn't really make any attempt to adjust (especially when you introduce mechanics with debt).
So maybe it saves coding, but in my experience it's not much different than traditional CPU opponents - with the exception that it absolutely obliterates my phone's batter life.
I worked on the game, happy to answer any questions!
I almost feel there should be Dominion expansions that are purposely never released to digital, to prevent people from rapid, isolated training, and to promote the in-person physical interaction of board game play.