I suppose as with ordinary pub quizzes, they can become dull when the same team wins every week/day/whatever.
I’ve started doing an online quiz once a week with a few friends. For a few weeks on the spin, we kept finishing second to the same team. The quizmasters introduced a few extra rounds that can’t be Googled, and the couple of weeks since we’ve won and the others have fallen away 🤔.
But although it’s fun to be competitive, I’d imagine unless we slip up soon others will get bored of us too.