Pep Guardiola already built up a very strong and dominating Manchester City in Premier League. If Manchester City fire him, many clubs and coaches will feel very happy with this decision. There is no guarantee that if Manchester City keeps Pep Guardiola, they will dominate Premier League again or just no more domination but still manage to win Premier League titles sparsely.
So where is that dominant City? Why hasn't they scared anyone this season? In case you forgot, City were champions before Guardiola arrived and if they can maintain the same level of spending, City will be champions after he leaves.
Guardiola, coaching top teams (Barcelona, Bayern and City) managed (lol) to become the first coach in the world who spent more than 2 billion on transfers. I think I know where his secret to success is.