I think in general, people just dont value the "box safeties" who dont turn the ball over.. Dont consider them elite if they not in coverage even if they are highly valued (NFL dont pay people even if they valued lol and Derwin is one of highly paid in league)
I think Downs is overrated by media because of the teams he played for buttt coaches love him also which when you watch the tape, he just doesnt make many mistakes at all, coaches LOOOOVE that lol.. But he not making splash plays so he seem ho hum.. I would never draft a in box safety that high tho, I remember reading some study on roster build for super bowl teams and wasting 1st round, especially that high on safety just seems dumb. Which I think where the overrated comes from..