Preface: PIAA in Pennsylvania is split into 12 Districts. Each district essentially operates as its own small state association. The only thing they don't control is school classification, player eligibility, and playing calendar. Leagues, schedules, playoffs, etc are up to the district. And there's a big disparity in size of district.
District 8 has 6 football teams (known as the Pittsburgh City League), District 7 has over 120 (known as the Western Pennsylvania Interscholastic Athletic League, aka the WPIAL), and District 10 has 40, give or take.
District 8 has always operated as one league run by one school district. District 7 has long since operated on a district-wide alignment system. The WPIAL dictates what league the teams play in for all sports, and sets their schedule (except for the first game of the year). Unlike other districts, the geographic reach of the WPIAL is by membership and not hardened lines on a map. There's overlap. For instance, Indiana, and Hollidaysburg all are members of WPIAL and not District 6.
Meanwhile, District 10 used to operate with an Ohio style setup of leagues determined by schools. Playoffs were a bit wonky working around that, since it was always by achievement and not a points system (i.e., you are the best team in your league in AA, you're in the playoffs in AA).
The leagues had teams of all different sizes in them.
The most noteworthy was the Northwest Football Conference. Which was a football only playing conference made up of Erie East, Erie Strong Vincent, Titusville, Meadville, Greenville, Warren, Franklin and Oil City. Spread over the entire district. Then there as the Erie County League, which was Northwestern, Girard, Fairview, Iroquois, Seneca, Harbor Creek, North East, and Corry. There was the French Creek Valley Conference, which was smaller schools south of Erie County. There was Maplewood, Saegertown, Cambridge Springs, Union City, Conneaut Lake, Conneaut Valley, Linesville, Lakeview, and Cochranton. South of that, was the Mercer County Athletic Conference, which had the league split into 3 parts (but schedules covered the entire league) for AAA Slippery Rock, Hickory, and Grove City; AA with Wilmington, Sharon, Mercer, and Reyolds; and A with Sharpsville, West Middlesex, and Kennedy Catholic. There was also General McLane, Fort LeBoeuf, Cathedral Prep, McDowell, and Central Tech, but I forget how they were situated.
This format lasted for a long time. The NWC teams played in the ECL, FCVC or MCAC for all other sports.
Until, the schools were just tired of scheduling. One, the NWC decided to become an all-sports conference in the early 2000s. Which forced Greenville out because though they could handle the travel for football, they weren't about to do it as a small school for all over sports. So, they went to the MCAC for a few years. But still, scheduling issues remained.
So, early/mid-2000s, the district voted to switch to a region setup (basically, what has been discussed here), where the District would assign teams to a region, and schedule their games. And let the schools only worry about scheduling their non-region games.
For the first cycle, it was basically:
MCAC became Region 1(A) and 3(AA). FCVC became Region 2 (A), and ECL became Region 4 (AA). NWC and City/large schools became Region 5 (AAA) and Region 6 (AAAA). Then, the realignments really started moving teams around. Saegertown got bumped to 2A, so they were in the south with all new teams in R3. And struggled. Northern teams did everything they could to stay away from Cathedral Prep.
Overall though, it's been 20 years and the schools have no intention of moving out of the region setup. It works. Sometimes you aren't in a region with a team you regularly play. So you just schedule them non-region yourself. It hasn't been the big scary thing Ohioans seem bent out of shape about.
Are their flaws? Certainly. But if you look around Ohio and see the constant reshuffling of leagues, then you realize the problem with the current system is not being addressed, either. And it's getting worse. MVAC anyone?
Other states do it, and it works. Some districts are far bigger than anything Ohio has to deal with. Where games are hours away in-league. While Ohioans are complaining about 40 minute drives. As someone else said on here... grow a pair.