I have softened my stance on Morris's Hall of Fame credientials is recent years. I don't consider him a big-game pitcher (not after watching 1987), he didn't "pitch to the score" and I don't care about "most wins in the 80s", but he was the most durable pitcher of his era and was the last of the complete game pitchers. Looking at 1980 forward, he had 165 CG. The closest one to him is Roger Clemems with 118. Even if you go back to 1975, he is still #1. although not by as much: Morris 175 Blyleven 165 Ryan 137 Tanana 129 Niekro 127 Carlton 123.
https://www.sports-reference.com/stathead/baseball/player-pitching-season-finder.cgi?request=1&match=player_season_combined&order_by=p_cg&year_min=1980