This.
As McDermott would say, "nothing is guaranteed, everything is earned".
Every year some teams go on a tear early in the season and then fade (2020 Steelers, 11-0 finished 12-4 and got washed in the WC round). Other teams are up-and-down but solidify their play and make the playoffs or even win the Superbowl. In 2021, the Chiefs were 3-3 and then 3-4 at one point, before winning 8 and a row and ultimately losing to the Bengals in the conference championship, I think in part because "13 seconds" the previous week took everything they had.
Does it look like a cakewalk, no it does not, but sometimes when things look like a cakewalk (Steelers) one needs to beware a House of Cards.