> I support this, up to the point where a second-grader has to carry four textbooks and four exercise books around on their walk to school; from the rucksack weight to body weight ratio they might as well be training for the marines.

I went to school a million years ago, but IIRC we kept our textbooks in the classroom until middle school (7th grade for me). Maybe one textbook might go home with math homework or an English project. For my kid, they would usually just send worksheets home; which is ok, but if you wanted to reference not on the sheet, too bad. Post-covid, there's a lot more dependence on google classroom with all that comes with it (but maybe that's also how the upper grades were working anyway)

E-readers with textbooks loaded could work, but hopefully the textbooks are tuned for the medium.

Anyway, isn't a heavy backpack a secret fitness program???