Classroom size

I understand the need to have higher student to teacher ratios. However, it’s been proven that classroom management is degraded as classroom sizes get larger. One way to mitigate classroom management is with more assistance (aids, parents) in the classroom. With all that money schools got from legalizing marijuana (shell game that didn’t actually help school funding), and federal per student subsidies, why can’t schools help teachers with classroom management and in tern increase effectiveness of learning environment?