How is the topic of carrying books addressed in the schools your children attend?

My kids used to carry several kilograms in their backpacks at some point. They had to have a book for each subject + a notebook + sometimes some exercises. Additionally, a pencil case, food, drinks, and additional materials needed for art classes. Parents began to rebel, saying it couldn't go on like this. There was talk of lockers, but the school doesn't have the money. So maybe some parent fundraising, but there were few volunteers for that as well. We suggested that they carry books in pairs, but it turns out that some teachers see a problem in that. And how is it in your kids' schools? Do they have any solutions for this?