I watched a really nice breakdown of CeeDee's route running by a college receiver coach on youtube the other day and the consensus was that CeeDee is ready to blow the doors off the NFL this season and a large reason was that his route running is becoming increasingly more refined. During the breakdown there was a specific emphasis on the attention to detail in some of CeeDee's routes that indicate a very good understanding of the WR position.
This is interesting because CeeDee did not enter the NFL known for his route running. He largely won by just flat out being more athletic than everyone and being a YAC monster however his game seems to have become more well rounded in the NFL.
The receiver coach making the video said he would not be surprised if CeeDee is regarded as the best receiver in football in a year or two given his trajectory and skillset. I'm not saying that his opinion is indisputable fact but I've been seeing similar takes from other good football minds. Only time will tell, but all the tools are there. As long as Dak can get him the ball, CeeDee is poised to really run it up this year.