How do you upgrade from a legitimate top-10 quarterback?
This question would only ever be a thing in Minnesota, to have a quarterback playing so well but still be in doubt whether you would like to give him an extension or not.
Letting Kirk Cousins walk or trading him would take the Vikings back at least 5 years and would start an official rebuilding process. Something that makes almost no sense considering the amount of talent all over this roster. You have an offense operating at a top five level, even with all the limitations of a terrible offensive line.
Taking out your quarterback and trying to experiment, with a rookie quarterback or a quarterback you trade for isn’t intelligent. Especially when there is genuinely no need for a reshuffle.
The Minnesota Vikings have the youngest offense in the NFL (24.8). With only two starters over the age of 30, the future is very bright for this group. The two members of the offense above the age of 30 are Kirk Cousins and Adam Thielen, both of which are still performing at an elite level.
There is currently no reasonable alternative to Kirk Cousins, so letting him go would literally be gambling your future with this incredible young group of players on offense.