Open to your idea(s).
Bob Gibson had 28 complete games in 1968. There were 34 in all of MLB in 2023. Now, Gibson was an athletic freak, but there were many starters with double-digit complete games stats back in the day. I’d venture there were fewer arm injuries. Now, everyone has to throw close to 100 mph.
Pitch like Greg Maddux - yeah, I know, easy to say; next to impossible to do - and don’t walk anybody. (Second to Robin Roberts in the “live ball era” in lowest walk rate. Having faced over 20,000 batters and not many walks and a good deal of those were intentional.)
I would bank on the game being better if there were far fewer relief specialists. I would venture there would be far fewer arm injuries and far fewer Tommy John procedures if there were to be a change in pitching thought.