At what point did kids lose the desire to learn?

Years ago, I thought that being a math teacher was a simple job. You present material in a learnable manner, answer questions, and ultimately make success attainable, while students learn the material and ask questions when they don’t understand. That’s how it was for my grandparents, parents, and myself. However, that no longer seems to be the case. I don’t see the majority of students performing their core responsibilities of actively engaging with the lesson, asking relevant questions, and studying. When did the classroom dynamic change so drastically? When did the drive to succeed and meet expectations fizzle out? When did parents decide that education was no longer of any importance for their child’s future well being?