I wouldn't blame MLB for any lack of youth supporters. Look only to the digital world with smart phones, video games, etc. Unfortunately, our span of attention gets less and less as we continue the march toward AI, etc.
Baseball is the same game today as it was when I was growing up in the 50s-pitch ball, hit ball, catch ball. It was popular with kids both playing and watching even when the Rams were here playing in the Coliseum from 1946 forward. The L.A. Angels were a Cub farm team that played in downtown L.A. and I recall the miniture Wrigley Field on Avalon Blvd was always packed. They also had high ratings on KTLA with only two cameras to cover the field.
No-baseball hasn't changed. Our lives have changed.