Just because a player didn't have a P5 offer doesn't mean they can't be great. Brady Christensen, Chris Wilcox, Dax Milne being prime examples and then these players who all had zero FBS offers:

RB Tyler Allgeier
RB Jackson McChesney
FB Masen Wake
WR Neil Pau'u
TE Isaac Rex
OL Clark Barrington
DT Atunaisa Mahe
LB Payton Wilgar
DB Keenan Ellis
DB Isaiah Herron
DB George Udo
K Jake Oldroyd
P Ryan Rehkow

A few of those guys are legit NFL prospects.