It does not have to mean going into the top 5. Most teams that are drafting in the top 5 have broken teams (lots of them missing draft assets in order to move so high).
Desperation and lack of long term job security in the front office is the biggest reason for failure of young QB’s, coaching staffs, and the aforementioned front offices. Forcing the pick early and then playing the QB way too early are the results of this all too common environment.
Also, since so many franchises clear house so often, it leads to a cycle that feeds itself. The biggest thing that I think leads to fairly consistent regular season success in Dallas is ironically the same front office and draft personnel year after year.