I don't know the others, but I played Terraforming Mars and, compared to MtG, it is a very simple game - even without taking into account the vast difference in number of available cards.

In TM there is almost no re-using of cards. Once a card is played, it either is discarded (red), provides a one-time bonus (green) or provides passive/active effect (blue). Only blue cards could be considered as being re-usable, but even that is only as far as the actual passive/active effect goes (which is separate from the effect it may generate when entering the game). Compare it with MtG, where many cards provide effects which allow discarded cards to be returned to the game (ranging from simple "ressurect creature" effects to such that allow shuffling whole stack of discarded cards back into the deck).

Also there is no stack in TM. And gaming the stack to your advantage is one of the core mechanics of MtG. A card you played may have different effects depending on cards your enemy plays in response, and these may have their effects altered by the cards you play in response, etc.