The Splendor part was a but confusing. The author's point is that the simple strategy has no meta, because players can't interfere with each other. It's just a race. But the strategy of saving up points opens up a metagame because players can now interfere with each other, so the game becomes about guessing opponent strategies and counterstrategies.

Another analogy is a bicycle race. You could have everyone run separately and compare their best times. But by racing together, you get peloton and team effects where players can attack opponentns and support teammates, but expose weakness that could be exploited, and the success of an act, like passing or drafting, depends on how others react.