It's not as Virgil is a late bloomer, he just made the step to an elite team way too late. Van Dijk was impressive during his Groningen days. I remember Ajax and PSV being heavily interested. While both had doubts about his character, as he was seen as lackluster and nonchalant at the time, Ajax were targeting him and Mike van den Hoorn and chose the latter. PSV chose Bruma, whereas Feyenoord had two nice talents at CB already (de Vrij and Martins Indi). He already was a force back then, but his footballing skills has definitely picked up. I remember big teams being interested in Virgil when he was still playing for Celtic, they all felt the step to the elite was a little too big for him and he proved them wrong. His time with Southhampton made them a believer, but he could've made the step to a Liverpool years sooner.