[yad]

The question of which activity requires more skill isn't really well-defined. But by what most people consider skill, I think it has to be chess. The proof is really in the amount of effort it requires to become world class at either. There are tons of players who pick up poker at 18 or 20, play and study for a few years, and become world-class players. OTOH not even the greatest chess prodigies can even become grandmasters, let alone truly world-class players, without decades of full-time study.

The fact that computers are a lot better at chess than at poker is pretty irrelevant IMO. It just means that it requires less skill for someone to program a computer to play chess than to program a computer to play poker. This is very different from the question of whether it's easier to play poker or to play chess. Computers are also lousy at bridge, for example, and almost nobody would say bridge requires more skill than chess.