The generalizations being made here are cute.
Spees guy vs possession? What's the cutt off point? I see 200 lbs WRs that you simply can't jam at the line, and I've seen 6'5 230 Mike Evans get handled by a DB 5 inches shorter than he was.
Most WRs in the league fall into the "possession " category. It's not just running good routes vs pure athletic ability...it's understanding your particular offense and the players around you , and being able to physically execute your assignment.
Juaun Jennings absolutely has many intangibles, speed at one of them, and his hands aren't as consistent as you'd like for a WR running 4.8. Speed would absolutely help him. It's not overrated one bit lol...
What keeps him around is that he blocks furiously and plays with fire. He breaks tackles and he's a good teammate.
But you ain't winning the division with a bunch of marginal athletes at WR that just run great routes haha.
There are deep threats and "possession " WRs. Not counting combo players like Deebo.
You need a certain level of speed and explosive abilities to perform at the skill spots in the NFL. That's a fact.