A boatload of old people died in 2020...
MLB attendance is up in 2023 than it was in 2019. It had been going down over the years and hit a low in 2022. The spike in attendance in 2023 and the average age going down since 2019 would suggest more younger people are interested in baseball. I would think it's a combination of shorter games with less watching pitchers stand on the mound picking their butt and gambling.