Someone once asked about their cat that wasn’t interested in catching mice. My answer to that was maybe the mouse is hiding where your cat can’t get him. Your cat may not care about the mouse because he’s well fed.
When my cats were kittens they were never taught by their mother how to kill mice. They have caught mice, but they don’t kill them, they just play with them and let them go. Kittens learn from their mothers and if you watch nature programs you will see a lioness teach her cubs to hunt.
Since cats are part of the larger cat family the same thing would apply.
My cats are well-fed, especially my overweight female who eats more than her brother. They have toy mice they like to play with so they don’t feel the need to kill real mice. Real mice to them are just fun toys which I have to take away from them (with an oven mitt) and drive it far away to another location.