Your grandkids are mistaken. My teen daughter reads and reads. When she was in the fourth grade she had her own home library, with well over a hundred books.
When she was in second grade we found out several of her classmates had not one book at home, so we sorted through hers, and came up with about forty to donate to them. They all loved books, they just didn’t have any.
I held reading groups for her class after school sometimes. I read to them some, but mostly they read to me. They rallied to have the next turn.
I heard the chicken butt story so many times, I can’t imagine how I don’t know it by heart even now.
People read, so do kids.