I'm not even convinced Go is all that popular in Japan compared to Shogi or Mahjong. Even Gomoku (five in a row, no capture rule) seems more popular. I can't really say anything about the popularity of go salons since I have yet to visit one but I can't help but notice that the game is never included as a minigame in Japanese titles like the Yakuza series (which has all sorts of other board minigames) or even Clubhouse Games for the Switch (51 games, one of them Gomoku, but no Go). It'd probably take another Hikaru no Go to increase popularity again...