We're north of NYC - smaller baseball market than some of the posters here. Our HS is one of the bigger ones in the area with 1,400 students. We had three primary starting pitchers of which one played both ways and hit every game. He was our top hitter and one of the best players in the region - now in his first year at a D1 program in the NE. The other two starters were Jrs and were PO (my son was one of them). There were 2 lefties who pitched in relief and were PO and then several players who filled in when needed who also played in the field but none of the full time position players were also starting pitchers (except the one top player).
Most of the other schools in the region have their top pitchers also play the field and hit - my guess is that they don't have the numbers at those schools and knowing the players involved (most of them played travel against our summer teams since they were 9-10) they are also the best overall player on that team and it would be hard to replace their bat in the lineup - for point of reference several of these guys are 2016s and committed D1 as pitchers (including the other 2016 at our HS). There is usually significant drop off pitching wise in the rotation after these guys but the teams are still pretty good.
From what I've seen (coaching local town baseball and summer travel the last 7 years) there has been a big shift of players to lacrosse that is hurting numbers in baseball in this area. It doesn't affect our HS as much because we have the numbers but other teams seem to have fewer players over all. Whatever the reason we don't have teams with multiple pitchers throwing 90+ as described in the other threads going on.