The idea of pitching to contact is gone.
Look at the Phillies lineup, which is the worst or 2nd worst in the majors at the moment. There still isnt a single hitter that you can groove a pitch to, which was really not true 40-50 years ago, there were always a couple very light slap/singles hitters on most (all?) teams. Galvis is great example, he has hit 8th most of his career, but if you groove a pitch to him it is going out. Ruiz hit 8th for us for years, but was still dangerous if you didnt respect him.
Years ago pitchers did not throw all out on every pitch, they conserved themselves, they threw strikes when there was no one on base and they tried to get hitters to hit "pitchers" pitches. Now, every pitcher throws for the strikeout with every batter. Strikeouts have gone WAY, WAY up since those times, and it isnt that hitters are not fundamentally sound as so many old timers want to believe, it is because pitching has advanced and guys now throw harder with more cut on pitches. Great pitchers are great pitchers and can survive in an era, but it is the middle and lower skilled guys that have changed. Now you regularly have guys at the end of your pitching staff that throw 95+ and have 1-2 good pitches. That was an ace 50 years ago.