I don't think Manchester City's rivals are waiting for Pep to leave (some are but not all) so they could take that opportunity to be at the top as always, no. Pep Guardiola's presence is what's making the EPL and winning the title more challenging and if as a coach you feel you're good enough then win the title when the best is around not wait for the best to be eliminated from the equation before calling yourself a good competitor. If he should quit his position as the City boss I would like to see him coach a national team let's see if he can keep up with the pressure of coaching a national team.
Yeah right, the dominance of Manchester City will definitely end up just waiting for time and we know that no team can maintain glory for decades, now we can see how Manchester City has a gap and also competitors can catch up 2 draws 2 defeats are proof that they have a problem. I have estimated that Manchester City will go through the golden era and the other team will replace them, Chelsea and Arsenal might be the next best team for the next 2-3 seasons.
One thing about the Citizens is that no matter how they struggle to get back to winning ways you can never see the coach or any of the players coming on air to say this is why they're having issues or because of too much fixtures that's why, no you can't hear such complain from them, they'll try as much as they can to not let people see much of their frustration, Pep has given these guys that idea of always maintaining their cool while on air.
Before either Chelsea or Arsenal can take over from City completely in dominating the league I think that will be when Pep Guardiola is no longer with the Citizens, even when he's no longer their other teams will step up too to compete for the title, is not only City who can make the EPL hard for other teams, every season we see how some of the smaller clubs get transformed to be at their best so is going to be a long ride for the big 6 to always be at the top.