Continued from above again:

Admin churn and policy changes have a direct and deleterious impact on teacher, student, and school performance. I can't focus on teaching academics if I am supposed to reteach classroom policy changes at random times throughout the year. Policy changes can take weeks to months to integrate into a classroom.
Teachers who are whipped back and forth between admin and policy changes don't have a moment to settle in and focus on what they were hired for. Instead they juggle the ever changing classroom culture, incorporating morphing policy decisions about how their classroom should be run, and socially adjusting to staffing and admin changes. There is no time to settle in and so burn out and nihilistic expectations take shape in many teachers.
This description is only a small part of the problem with admin and policy churn in school systems.

Parents and parenting styles are other pernicious issues that are extremely controversial. These issues directly affect students and indirectly affect teachers. Whether it hurts or not to admit, parents have power over the school system. Many people outside of the school system focus on teacher unions and large scale public school administration as a main pain point.

Yet when teachers and school administration are under threat from being sued due to happenings in class because parents don't like what occurrs, the school system adjusts to accommodate those parents' wishes. At some point the school system begins to become an inane policy labyrinth to avoid lawsuits. There are plenty of lawsuit examples if searched on any search engine. These lawsuits set precedents in our county for how policy will look in coming years.
As for parenting styles, these are varied and diverse. Every household has their way of rearing children. Yet when you take diverse children and put them into a class of 20+ students and typically one teacher the varied rearing styles become a pain point when applying teaching standards. In one highschool class you can have students reading on a college level, while others are emerging eighth grade.
Has the system failed them? Sure, the system didn't catch them in time before they moved on and moving them now would take months due to admin churn and County backlogs on the other hundreds of thousands of students issues weighing down a bloated inept system. Or maybe the previous school was worried that funding would be cut causing admin to push through many students that should have been retained because if not the "greater good" of hundreds of other students would be impacted by funding cuts.
But it isn't just the school systems that have failed students, so have the parents. Sometimes students aren't held back because of parental intervention. These interventions can be lawsuits or putting up enough of a fight that the county relents and allows the student to progress. The latter has happened four times in my classes and many more times to my other teaching peers. When teachers hold students back and parents put up a fight by bringing in the county, the school's admin and teacher have to follow the county dictates, which almost always fall on the parents' side. A cause for this is teachers are not considered experts when it comes to education. There are a myriad of reasons for this ranging from poorly funded college education degree programs, to society's mistrust of experts, to a belief parents know their children the best. As exemplified by the recent pandemic and social media post hating "lazy teachers who want to get out work" , mistrust in teachers and their teaching abilities are pretty apparent.