Earlier quoted context omitted.
If I recall, there are more possible chess games than atoms in the universe. So even if you were to quantify toughness as number of possible decisions, it would still be completely off. However, in both those games, a lot of the plays would be ridiculous. It's easier to try and measure toughness by the time/effort it takes to be competent or the best. In this case I would say chess is hands down much tougher.
Sure, the number of possible moves is huge in both games. However, it's more about the number of relevant moves at a given game state. Alpha-beta algorithms for chess can do a much more thorough search than their poker-specific extensions and related methods like MCMC. I suppose if you're measuring difficulty of a game as how difficult it is for a human player to beat the current masters, then that seems a little unf…
That has to be a joke to compare the games that way. Even here you mention number of relevant moves at a given game state. I have to be misunderstanding that. Bet/check/fold vs say half dozen candidate moves?
I've been assuming difficulty for a human the whole time, to attain any level of skill. Since the chess community/theory is more established, it's going to be a more difficult game.