> There is nothing that, in principle, makes MTG different from poker or bridge

Only in the most general form they are games with cards and hidden information with a state space that some form of tree search can theoretically play out.

The difference is the size of the search space. In MTG the search space is unimaginably huge. It would make Go's search space look like a spec of hydrogen in the middle of the universe.

It would require completely different techniques to produce a computer good at MtG than one that is good at bridge.