But, Bridge wasn't in the games.
More seriously: The second game is out of question. With King's Court, Bridge is clearly better. No doubt. But at least Butcher comboed well with Merchant Guild here.
And the first game would have probably worked well with Bridge too, sure. Those weren't games to show that Merchant Guild is superior to Bridge.
In mega turns there is usually no big difference and Bridge is often better.
But in many games you can't more than like 4 Merchant Guilds in play for example because of lack of draw. 4 Bridges usually don't win you a game (it depends on the board, sure), but if you get 4 Merchant Guilds in play and get 20 coin tokens you are at least probably guaranteed to get a Province each turn until the end of the game what often means game over for your opponent.
Also, playing with Merchant Guild is just more fun.