Its been 4 years. The team has had weaknesses that were costly in all 4 of them. The defense has been the big problem on the field all 4 years. Garrett and the coaching staff was also a big problem.
As far as Dak being handed things, he had a great Oline in 2016 and 2019. He has had a good running game all 4 years. His best pass catchers were last year and he flourished with them. Didn't have a legitimate WR1 until 2nd half of last year. WE have seen the difference since.
NO way Cowboys have been a contender the last 3 years. 2016 was the best team, but still had a bad defense and coach.
So this notion that Dak has been surrounded by tons of talent is only 1/3 true. Offense maybe, defense no, coaching no.