I'm sure this is true to some degree. We have a lot more information now, better technology, better training regimes, nutrition, etc. But I think that's also the problem. We don't get to see guys pitch into the 7th and 8th inning anymore because we have data to tell us you're better off going to the bullpen at that stage. We don't see as many batted balls fall in for hits because the defense knows based on science and data exactly where to position itself. And the velocity of modern pitchers, while impressive, has led to several unintended consequences that have greatly diminished the value of the position and put them at far greater risk of injury.
I don't miss watching Jamie Moyer. I respect the guts and guile it must have taken for someone with his limitations to last that long in the majors, but I never found guys like him particularly fun to watch.
I miss watching a guy take the ball who knows he's going to be out there 7 or 8 innings. I miss watching a guy who could probably dial it up to 98 or 99 have to get by with 94 or 95 because he knows it's a marathon and not a sprint. I miss watching the best pitchers figure out different ways to get you out in your 3rd or 4th at bat rather than facing you once or twice and passing the buck to the next bot throwing 100.
It's not fair for me to hold this against the current players because they don't have any choice in the matter. A guy like Skubal is an incredible talent who's probably more dominant and fun to watch throwing 95 pitches than he would be throwing 115. But the sport itself has suffered because the craft has been diluted. It's a good example of how having more information and smarter people running the show doesn't necessarily translate to better entertainment.