Way too big for whom? While it is a common trope that we see classrooms with 25+ children/teenagers as too big, I have rarely seen a comment that complains on university lectures hosting too many students. How come? Good Lecture-design is a direct function of the percentage of students in a classroom who understand the input without lots of clarification needed. There's a reason why we have different forms of teaching & learning in universities. Big passive lecture halls make sense to transfer basic information to a lot of people. Small study groups make sense to deepen knowledge on a topic, midsized seminars are useful to stimulate students in questioning their own understanding of a topic and getting rid of blind spots in their conceptions. Classrooms are similarly sized (at least in my country) compared to university seminars. It is not the number of pupils that is too high. It is the architecture and structure of teaching and learning in schools that doesnt account for different learning/teaching formats and even more so ill-equipped teachers. Studies have found again and again that classroom-size, even though often discussed, are actually a minor factor in the quality of teaching and learning. The number one factor by large is the teacher. If you have a capable teacher, who can lit the interest of their students, performance goes up. If you have an unmotivated, badly/barely trained teacher (not necessarily trained as a teacher, but as a storyteller and facilitator), you can shrink the classroom as much as you want, the students won't learn anything.

The same goes for assisted homework-sessions. If the adult can ignite the interest of the student and get past the "I have to do this, but I don't even know why", it will work. Otherwise...well, ChatGTP provides at least a baseline of quality in explaining and rephrasing learning material.

So yes, I totally agree, children need human attention for a good development, but not necessarily in their study-time. If you look at the "hole in the wall"-experiments by S. Mitra, you'll see that the attention of a granny who asks with earnest interest what a child has learned today, the kid massively profits from that interaction even though the granny has no clue what the kid is talking about.

Children still learn ways how to process input at young ages, smaller classes are likely beneficial for everyone as more attention is awarded to them. University students do not need such attention, students do miss lectures and catch up on them independently if they need to.