South Korea has left hard cash in the dust. The country is a virtually friction-free, digital payments dream, where just a fraction of purchases are done in notes and coins. Park Se-hwa’s bookstore, on a commercial street in Seoul, is a holdout. Inside the narrow door, a sign reads: “The best way to support the bookstore is to pay cash.” She bristles every time she processes a purchase by card, since it means she has to pay a fee to the bank, and refuses to use digital payment services at all.⁠ ⁠ “Those big companies are the public enemy of booksellers,” she said.⁠ ⁠ Her fears reverberate as high up as South Korea’s lawmakers and antitrust commission, who have spent this year attempting to rein in the country’s vastly powerful tech giants. Kakao and Naver are the main targets: They have rapidly expanded their tentacles into South Koreans’ digital lives. The government worries that their growth is coming at the sacrifice of the country’s small businesses. With South Koreans’ buying acti...