It's not a question of laziness it's a question of prioritization and opportunity cost. The logical conclusion of your argument is Apple has lots of money ther

It's not a question of laziness it's a question of prioritization and opportunity cost. The logical conclusion of your argument is Apple has lots of money therefore they should have finished everything already. The small team assigned to port Books to iOS16 probably decided that spending a lot of effort porting the one animation is not worth the opportunity cost that could be spent on literally anything else.