You want to talk about football as it's played on the field as opposed to qualitative generalizations like 'good' and 'great' which are based on little more than emotion?
His shuttle and 3 cone scores which actually correlate to NFL success are elite. They compare with guys like Mack and Miller coming out. At OSU he was routinely double and triple teamed because no single man could block him. While OC's gameplanned him, his own OC ran zone blitzes that keyed off of how they blocked Bosa. He was named his conferences best defender two years running.
Despite that attention, he still managed 70 pressures in 10 games for all the handwaving at his sack totals. He can succeed on the dip and rip, swim, bull rush, and knows how to break down a tackle using leverage and balance to dominate. He has the body control and explosion to break down and finish. He knows how to convert speed to power and he knows how to use his hands to keep the blockers hands away while maintaining his rush.