You act like our roster is the 85 Bears or the 93 Cowboys. You're barking up a false tree on that. People think the Cowboys have a strong roster, not an overwhelming dominant one that is so talented it should blow past any other team.
Every single premise you are basing your arguments on is false, from this, to the idea that Garrett's ultimatum (if it even existed, which there is no evidence of) had nothing to do with him having had 9 years already and that the same ultimatum applies to every subsequent coach that wasn't even on the radar at the time, to the idea that a Super Bowl win is such a routine expectation that it should be a certainty for a team with a good coach and roster. On top of that, you are completely ignoring the fact that there are other teams with strong rosters and strong coaches competing for the same prize, and instead are treating it as if McCarthy is a strong coach that would only apply to the Cowboys. The goal is to be among those teams that are a true contender every season knowing that the more seasons the team has a legitimate shot to win it all, the more likely the team is to win it all.