there's not a lot of middle school ball in our area but the catholic schools have a league. my son went to a catholic for middle school (from an independent private) and played in 6th grade. It was a definite step backwards, baseball-wise and, as he didn't know a lot of the kids (most of them had come up through elementary school and were good friends for years), he was the outsider looking in. Add to that he was one of the only kids who took baseball somewhat seriously and cared about his performance, and that one year was his only middle school ball experience. level of play was, overall, bad. there's only 3 kids, I believe, who are still playing baseball (2023 class). the 4th best player on the team plays hoop. the 5th best plays football and hoop. I don't believe anyone else on that team plays any sports in HS.
the icing on the cake is that team won the championship. as bad as their talent level was, they were better than all the other teams in the league.