How can you possibly back up this statement?
It's impossible to definitively prove one way or the other if another year hurts, helps, or has no effect on a players draft stock. All I can say is I only see a small % of our players actually get better every year they're here.
Take our Top returning players in terms of NFL potential this year vs. last year:
DeeJay Dallas - Was better this year, but had injury problems.
Garvin, Shaq, Pinckney - About the same in 2019 as 2018.
KJ Osborne - Was a little better. Had 900 yds receiving at Buffalo in 2018, had 500 yds receiving at Miami in 2019, but showed he can play at P5 level
Jeff Thomas & Bandy - Seemed to regress, or at least didn't have as good years in 2019 as 2018
I'd say 2 draft stocks went up (DJ, KJ), 3 stayed the same, 2 went down. 2 out of 8 (20%) improved.
People only want to acknowledge the small % that improved, and forget or don't acknowledge the larger % that didn't.