I think an undertalked property of games is the interpretability of feedback. Chess and poker are two ends of the spectrum here. In chess, you usually notice when you did something wrong; especially now that you can just ask the computer. In poker, it can be extremely difficult to know what mistakes you're making. This means you can play and play and be bad and not ever realize why. In fact, this is probably what I did; I never succeeded at poker.
Not to say that you can't also play chess without improving if you just don't have the mental tools, but at least one necessary criterion (noticing what you did wrong) is given.
Dominion is somewhere in the middle. Much easier to notice mistakes than in poker, probably harder than in chess. I very much notice a difference between chess, though. I just played and easily beat the 1500 chess bot, I think the most convincing win I've had so far. Probably some variance here, but it the engine told me I made no 'mistakes'. I draw a direct line between that and the fact that it's early in the day. I tend to be more mentally fit early in the day.
I don't notice the difference in dominion, but it's probably there.