Basically, all this talk of variance and standard deviation is a derail. The little bit of Bayesian vs Frequentist back and forth is amusing (Pro tip: In a Bayesian vs Frequentist challenge, always bet on the Bayesian), but it too omits the main point.
The OP is true, and at the same time it is ridiculous.
If you are playing poker at a table full of people with skill equal to yours, you are doing it wrong.(*)
If the sixth best poker player in the world sits down with the five better players, things will not go very well for them; but if some kid who has read, say,
Exploitative Play in Live Poker goes straight from their job flipping burgers to the local cardroom to play 1-2 NLHE, they stand a pretty good shot of being able to beat the game long-term.
Poker is fundamentally about playing against weaker players and exploiting those players' weakness to take the money. This is why game selection is a fundamental skill of successful poker.
Poker is, at root, a hustle, a way for the smart money to take advantage of the dumb money.
In the artificial situation described in the OP, by construction no one can hustle anyone else. Does variance matter in poker? Of course it does. But successful players can fade the variance, and in the long run they are going to prevail over the fun players.
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(*) Yes, a home game with your pals can be well worth playing when no one has an edge.