You are the only one deceiving yourself with the believe that they will not be able to win it again. This season before they succeeded in winning the treble, there was also a lot of doubts about if the club will be able to go all through and when everything but they did. Next season it would not matter what we think or if you believe that they will not be able to defend the title again. Manchester City will come all out again to try to win the premiership, the Champions League and any other competition that they find themselves in. As far as Pep Guardiola is still the coach, the team standard will not drop.